diff --git a/libraries/entities-rendering/README.md b/libraries/entities-rendering/README.md
new file mode 100644
index 00000000..58128c07
--- /dev/null
+++ b/libraries/entities-rendering/README.md
@@ -0,0 +1,26 @@
+# Entities Rendering API
+
+The Entities Rendering API provides events and utilities for registering and working with entity renderers.
+
+## Registering Custom Entity Renderers
+
+Entity renderer registration should be done in a listener to the `REGISTER_ENTITY_RENDERERS` event.
+
+An example is shown below.
+
+```java
+package com.example;
+
+import net.ornithemc.osl.entities.api.client.EntityRenderingEvents;
+import net.ornithemc.osl.entrypoints.api.client.ClientModInitializer;
+
+public class ExampleInitializer implements ClientModInitializer {
+
+	@Override
+	public void initClient() {
+		EntityRenderingEvents.REGISTER_ENTITY_RENDERERS.register(registry -> {
+			registry.register(CookieMonsterEntity.class, CookieMonsterRenderer::new);
+		});
+	}
+}
+```
diff --git a/libraries/entities-rendering/build.gradle b/libraries/entities-rendering/build.gradle
new file mode 100644
index 00000000..e98ba2c6
--- /dev/null
+++ b/libraries/entities-rendering/build.gradle
@@ -0,0 +1 @@
+setUpLibrary(project)
diff --git a/libraries/entities-rendering/entities-rendering-mc14w05a-mc1.14.4/build.gradle b/libraries/entities-rendering/entities-rendering-mc14w05a-mc1.14.4/build.gradle
new file mode 100644
index 00000000..0a350fdb
--- /dev/null
+++ b/libraries/entities-rendering/entities-rendering-mc14w05a-mc1.14.4/build.gradle
@@ -0,0 +1 @@
+setUpModule(project)
diff --git a/libraries/entities-rendering/entities-rendering-mc14w05a-mc1.14.4/gradle.properties b/libraries/entities-rendering/entities-rendering-mc14w05a-mc1.14.4/gradle.properties
new file mode 100644
index 00000000..bc56517e
--- /dev/null
+++ b/libraries/entities-rendering/entities-rendering-mc14w05a-mc1.14.4/gradle.properties
@@ -0,0 +1,5 @@
+environment = client
+min_mc_version = 14w05a
+max_mc_version = 1.14.4
+
+minecraft_version = 1.12.2
diff --git a/libraries/entities-rendering/entities-rendering-mc14w05a-mc1.14.4/src/main/java/net/ornithemc/osl/entities/api/client/EntityRendererRegistry.java b/libraries/entities-rendering/entities-rendering-mc14w05a-mc1.14.4/src/main/java/net/ornithemc/osl/entities/api/client/EntityRendererRegistry.java
new file mode 100644
index 00000000..e3fa0b53
--- /dev/null
+++ b/libraries/entities-rendering/entities-rendering-mc14w05a-mc1.14.4/src/main/java/net/ornithemc/osl/entities/api/client/EntityRendererRegistry.java
@@ -0,0 +1,24 @@
+package net.ornithemc.osl.entities.api.client;
+
+import java.util.function.Function;
+
+import net.minecraft.client.render.entity.EntityRenderDispatcher;
+import net.minecraft.client.render.entity.EntityRenderer;
+import net.minecraft.entity.Entity;
+
+/**
+ * A wrapper around the {@linkplain EntityRenderDispatcher} renderers map.
+ */
+@FunctionalInterface
+public interface EntityRendererRegistry {
+
+	/**
+	 * Registers the given entity renderer for the given entity type.
+	 * 
+	 * @param <T>     the entity type for which to register the renderer.
+	 * @param type    the entity type class.
+	 * @param factory the factory for the entity renderer to register.
+	 */
+	<T extends Entity> void register(Class<T> type, Function<EntityRenderDispatcher, EntityRenderer<? super T>> factory);
+
+}
diff --git a/libraries/entities-rendering/entities-rendering-mc14w05a-mc1.14.4/src/main/java/net/ornithemc/osl/entities/api/client/EntityRenderingEvents.java b/libraries/entities-rendering/entities-rendering-mc14w05a-mc1.14.4/src/main/java/net/ornithemc/osl/entities/api/client/EntityRenderingEvents.java
new file mode 100644
index 00000000..af74dc62
--- /dev/null
+++ b/libraries/entities-rendering/entities-rendering-mc14w05a-mc1.14.4/src/main/java/net/ornithemc/osl/entities/api/client/EntityRenderingEvents.java
@@ -0,0 +1,34 @@
+package net.ornithemc.osl.entities.api.client;
+
+import java.util.function.Consumer;
+
+import net.ornithemc.osl.core.api.events.Event;
+
+/**
+ * Events related to the entities rendering lifecycle.
+ */
+public final class EntityRenderingEvents {
+
+	/**
+	 * This event is invoked upon client start-up, after Vanilla entity renderer registration is finished.
+	 * 
+	 * <p>
+	 * Custom entity renderer registration should be done in a listener of this event.
+	 * 
+	 * <p>
+	 * Listeners to this event should be registered in your mod's entrypoint,
+	 * and can be done as follows:
+	 * 
+	 * <pre>
+	 * {@code
+	 * EntityRenderingEvents.REGISTER_ENTITY_RENDERERS.register(registry -> {
+	 * 	registry.register(CookieMonsterEntity.class, CookieMonsterRenderer::new);
+	 * });
+	 * }
+	 * </pre>
+	 * 
+	 * @see EntityRendererRegistry
+	 */
+	public static final Event<Consumer<EntityRendererRegistry>> REGISTER_ENTITY_RENDERERS = Event.consumer();
+
+}
diff --git a/libraries/entities-rendering/entities-rendering-mc14w05a-mc1.14.4/src/main/java/net/ornithemc/osl/entities/impl/EntitiesRenderingMixinPlugin.java b/libraries/entities-rendering/entities-rendering-mc14w05a-mc1.14.4/src/main/java/net/ornithemc/osl/entities/impl/EntitiesRenderingMixinPlugin.java
new file mode 100644
index 00000000..2f14636f
--- /dev/null
+++ b/libraries/entities-rendering/entities-rendering-mc14w05a-mc1.14.4/src/main/java/net/ornithemc/osl/entities/impl/EntitiesRenderingMixinPlugin.java
@@ -0,0 +1,52 @@
+package net.ornithemc.osl.entities.impl;
+
+import java.util.List;
+import java.util.Set;
+
+import org.objectweb.asm.tree.ClassNode;
+
+import org.spongepowered.asm.mixin.extensibility.IMixinConfigPlugin;
+import org.spongepowered.asm.mixin.extensibility.IMixinInfo;
+
+import net.ornithemc.osl.core.impl.util.MinecraftVersion;
+
+public class EntitiesRenderingMixinPlugin implements IMixinConfigPlugin {
+
+	@Override
+	public void onLoad(String mixinPackage) {
+	}
+
+	@Override
+	public String getRefMapperConfig() {
+		return null;
+	}
+
+	@Override
+	public boolean shouldApplyMixin(String targetClassName, String mixinClassName) {
+		if ("net.ornithemc.osl.entities.impl.mixin.client.EntityRenderDispatcherMixinNew".equals(mixinClassName)) {
+			return MinecraftVersion.resolve().compareTo("18w50a") >= 0;
+		}
+		if ("net.ornithemc.osl.entities.impl.mixin.client.EntityRenderDispatcherMixinOld".equals(mixinClassName)) {
+			return MinecraftVersion.resolve().compareTo("18w50a") < 0;
+		}
+
+		return true;
+	}
+
+	@Override
+	public void acceptTargets(Set<String> myTargets, Set<String> otherTargets) {
+	}
+
+	@Override
+	public List<String> getMixins() {
+		return null;
+	}
+
+	@Override
+	public void preApply(String targetClassName, ClassNode targetClass, String mixinClassName, IMixinInfo mixinInfo) {
+	}
+
+	@Override
+	public void postApply(String targetClassName, ClassNode targetClass, String mixinClassName, IMixinInfo mixinInfo) {
+	}
+}
diff --git a/libraries/entities-rendering/entities-rendering-mc14w05a-mc1.14.4/src/main/java/net/ornithemc/osl/entities/impl/mixin/client/EntityRenderDispatcherMixinNew.java b/libraries/entities-rendering/entities-rendering-mc14w05a-mc1.14.4/src/main/java/net/ornithemc/osl/entities/impl/mixin/client/EntityRenderDispatcherMixinNew.java
new file mode 100644
index 00000000..483bf82e
--- /dev/null
+++ b/libraries/entities-rendering/entities-rendering-mc14w05a-mc1.14.4/src/main/java/net/ornithemc/osl/entities/impl/mixin/client/EntityRenderDispatcherMixinNew.java
@@ -0,0 +1,38 @@
+package net.ornithemc.osl.entities.impl.mixin.client;
+
+import java.util.function.Function;
+
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Shadow;
+import org.spongepowered.asm.mixin.Unique;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
+
+import net.minecraft.client.render.entity.EntityRenderDispatcher;
+import net.minecraft.client.render.entity.EntityRenderer;
+import net.minecraft.entity.Entity;
+
+import net.ornithemc.osl.entities.api.client.EntityRenderingEvents;
+
+@Mixin(EntityRenderDispatcher.class)
+public class EntityRenderDispatcherMixinNew {
+
+	@Shadow
+	private <T extends Entity> void m_74922622(Class<T> type, EntityRenderer<? super T> renderer) { }
+
+	@Inject(
+		method = "<init>",
+		at = @At(
+			value = "TAIL"
+		)
+	)
+	private void osl$entities$registerEntityRenderers(CallbackInfo ci) {
+		EntityRenderingEvents.REGISTER_ENTITY_RENDERERS.invoker().accept(this::register);
+	}
+
+	@Unique
+	private <T extends Entity> void register(Class<T> type, Function<EntityRenderDispatcher, EntityRenderer<? super T>> factory) {
+		this.m_74922622(type, factory.apply((EntityRenderDispatcher) (Object) this));
+	}
+}
diff --git a/libraries/entities-rendering/entities-rendering-mc14w05a-mc1.14.4/src/main/java/net/ornithemc/osl/entities/impl/mixin/client/EntityRenderDispatcherMixinOld.java b/libraries/entities-rendering/entities-rendering-mc14w05a-mc1.14.4/src/main/java/net/ornithemc/osl/entities/impl/mixin/client/EntityRenderDispatcherMixinOld.java
new file mode 100644
index 00000000..e30891c2
--- /dev/null
+++ b/libraries/entities-rendering/entities-rendering-mc14w05a-mc1.14.4/src/main/java/net/ornithemc/osl/entities/impl/mixin/client/EntityRenderDispatcherMixinOld.java
@@ -0,0 +1,40 @@
+package net.ornithemc.osl.entities.impl.mixin.client;
+
+import java.util.Map;
+import java.util.function.Function;
+
+import org.spongepowered.asm.mixin.Final;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Shadow;
+import org.spongepowered.asm.mixin.Unique;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
+
+import net.minecraft.client.render.entity.EntityRenderDispatcher;
+import net.minecraft.client.render.entity.EntityRenderer;
+import net.minecraft.entity.Entity;
+
+import net.ornithemc.osl.entities.api.client.EntityRenderingEvents;
+
+@Mixin(EntityRenderDispatcher.class)
+public class EntityRenderDispatcherMixinOld {
+
+	@Shadow @Final
+	private Map<Class<? extends Entity>, EntityRenderer<? extends Entity>> renderers;
+
+	@Inject(
+		method = "<init>",
+		at = @At(
+			value = "TAIL"
+		)
+	)
+	private void osl$entities$registerEntityRenderers(CallbackInfo ci) {
+		EntityRenderingEvents.REGISTER_ENTITY_RENDERERS.invoker().accept(this::register);
+	}
+
+	@Unique
+	private <T extends Entity> void register(Class<T> type, Function<EntityRenderDispatcher, EntityRenderer<? super T>> factory) {
+		this.renderers.put(type, factory.apply((EntityRenderDispatcher) (Object) this));
+	}
+}
diff --git a/libraries/entities-rendering/entities-rendering-mc14w05a-mc1.14.4/src/main/resources/fabric.mod.json b/libraries/entities-rendering/entities-rendering-mc14w05a-mc1.14.4/src/main/resources/fabric.mod.json
new file mode 100644
index 00000000..3ad32c07
--- /dev/null
+++ b/libraries/entities-rendering/entities-rendering-mc14w05a-mc1.14.4/src/main/resources/fabric.mod.json
@@ -0,0 +1,26 @@
+{
+  "schemaVersion": 1,
+  "id": "osl-entities-rendering",
+  "version": "0.1.0+mc14w05a-mc1.14.4",
+  "environment": "client",
+  "mixins": [
+    "osl.entities-rendering.mixins.json"
+  ],
+  "depends": {
+    "fabricloader": "\u003e\u003d0.18.0",
+    "minecraft": "\u003e\u003d1.8-alpha.14.5.a \u003c\u003d1.14.4",
+    "osl-core": "\u003e\u003d0.9.0",
+    "osl-entrypoints": "\u003e\u003d0.5.0"
+  },
+  "name": "OSL Entities Rendering",
+  "description": "Entities Rendering API and events.",
+  "authors": [
+    "OrnitheMC"
+  ],
+  "contact": {
+    "homepage": "https://ornithemc.net/",
+    "issues": "https://github.com/OrnitheMC/ornithe-standard-libraries/issues",
+    "sources": "https://github.com/OrnitheMC/ornithe-standard-libraries"
+  },
+  "license": "Apache-2.0"
+}
\ No newline at end of file
diff --git a/libraries/entities-rendering/entities-rendering-mc14w05a-mc1.14.4/src/main/resources/osl.entities-rendering.mixins.json b/libraries/entities-rendering/entities-rendering-mc14w05a-mc1.14.4/src/main/resources/osl.entities-rendering.mixins.json
new file mode 100644
index 00000000..32057071
--- /dev/null
+++ b/libraries/entities-rendering/entities-rendering-mc14w05a-mc1.14.4/src/main/resources/osl.entities-rendering.mixins.json
@@ -0,0 +1,18 @@
+{
+	"required": true,
+	"minVersion": "0.8",
+	"package": "net.ornithemc.osl.entities.impl.mixin",
+	"compatibilityLevel": "JAVA_8",
+	"plugin": "net.ornithemc.osl.entities.impl.EntitiesRenderingMixinPlugin",
+	"mixins": [
+	],
+	"client": [
+		"client.EntityRenderDispatcherMixinNew",
+		"client.EntityRenderDispatcherMixinOld"
+	],
+	"server": [
+	],
+	"injectors": {
+		"defaultRequire": 1
+	}
+}
diff --git a/libraries/entities-rendering/entities-rendering-mca1.0.1_01-mc14w04b/build.gradle b/libraries/entities-rendering/entities-rendering-mca1.0.1_01-mc14w04b/build.gradle
new file mode 100644
index 00000000..0a350fdb
--- /dev/null
+++ b/libraries/entities-rendering/entities-rendering-mca1.0.1_01-mc14w04b/build.gradle
@@ -0,0 +1 @@
+setUpModule(project)
diff --git a/libraries/entities-rendering/entities-rendering-mca1.0.1_01-mc14w04b/gradle.properties b/libraries/entities-rendering/entities-rendering-mca1.0.1_01-mc14w04b/gradle.properties
new file mode 100644
index 00000000..406c9774
--- /dev/null
+++ b/libraries/entities-rendering/entities-rendering-mca1.0.1_01-mc14w04b/gradle.properties
@@ -0,0 +1,8 @@
+environment = client
+min_mc_version = a1.0.1_01
+max_mc_version = 14w04b
+
+minecraft_version = 1.7.2
+raven_build = 1
+sparrow_build = 1
+nests_build = 3
diff --git a/libraries/entities-rendering/entities-rendering-mca1.0.1_01-mc14w04b/src/main/java/net/ornithemc/osl/entities/api/client/EntityRendererRegistry.java b/libraries/entities-rendering/entities-rendering-mca1.0.1_01-mc14w04b/src/main/java/net/ornithemc/osl/entities/api/client/EntityRendererRegistry.java
new file mode 100644
index 00000000..d293b8f9
--- /dev/null
+++ b/libraries/entities-rendering/entities-rendering-mca1.0.1_01-mc14w04b/src/main/java/net/ornithemc/osl/entities/api/client/EntityRendererRegistry.java
@@ -0,0 +1,24 @@
+package net.ornithemc.osl.entities.api.client;
+
+import java.util.function.Supplier;
+
+import net.minecraft.client.render.entity.EntityRenderDispatcher;
+import net.minecraft.client.render.entity.EntityRenderer;
+import net.minecraft.entity.Entity;
+
+/**
+ * A wrapper around the {@linkplain EntityRenderDispatcher} renderers map.
+ */
+@FunctionalInterface
+public interface EntityRendererRegistry {
+
+	/**
+	 * Registers the given entity renderer for the given entity type.
+	 * 
+	 * @param <T>     the entity type for which to register the renderer.
+	 * @param type    the entity type class.
+	 * @param factory the factory for the entity renderer to register.
+	 */
+	<T extends Entity> void register(Class<T> type, Supplier<EntityRenderer<? super T>> factory);
+
+}
diff --git a/libraries/entities-rendering/entities-rendering-mca1.0.1_01-mc14w04b/src/main/java/net/ornithemc/osl/entities/api/client/EntityRenderingEvents.java b/libraries/entities-rendering/entities-rendering-mca1.0.1_01-mc14w04b/src/main/java/net/ornithemc/osl/entities/api/client/EntityRenderingEvents.java
new file mode 100644
index 00000000..af74dc62
--- /dev/null
+++ b/libraries/entities-rendering/entities-rendering-mca1.0.1_01-mc14w04b/src/main/java/net/ornithemc/osl/entities/api/client/EntityRenderingEvents.java
@@ -0,0 +1,34 @@
+package net.ornithemc.osl.entities.api.client;
+
+import java.util.function.Consumer;
+
+import net.ornithemc.osl.core.api.events.Event;
+
+/**
+ * Events related to the entities rendering lifecycle.
+ */
+public final class EntityRenderingEvents {
+
+	/**
+	 * This event is invoked upon client start-up, after Vanilla entity renderer registration is finished.
+	 * 
+	 * <p>
+	 * Custom entity renderer registration should be done in a listener of this event.
+	 * 
+	 * <p>
+	 * Listeners to this event should be registered in your mod's entrypoint,
+	 * and can be done as follows:
+	 * 
+	 * <pre>
+	 * {@code
+	 * EntityRenderingEvents.REGISTER_ENTITY_RENDERERS.register(registry -> {
+	 * 	registry.register(CookieMonsterEntity.class, CookieMonsterRenderer::new);
+	 * });
+	 * }
+	 * </pre>
+	 * 
+	 * @see EntityRendererRegistry
+	 */
+	public static final Event<Consumer<EntityRendererRegistry>> REGISTER_ENTITY_RENDERERS = Event.consumer();
+
+}
diff --git a/libraries/entities-rendering/entities-rendering-mca1.0.1_01-mc14w04b/src/main/java/net/ornithemc/osl/entities/impl/mixin/client/EntityRenderDispatcherMixin.java b/libraries/entities-rendering/entities-rendering-mca1.0.1_01-mc14w04b/src/main/java/net/ornithemc/osl/entities/impl/mixin/client/EntityRenderDispatcherMixin.java
new file mode 100644
index 00000000..24369cfa
--- /dev/null
+++ b/libraries/entities-rendering/entities-rendering-mca1.0.1_01-mc14w04b/src/main/java/net/ornithemc/osl/entities/impl/mixin/client/EntityRenderDispatcherMixin.java
@@ -0,0 +1,41 @@
+package net.ornithemc.osl.entities.impl.mixin.client;
+
+import java.util.Map;
+import java.util.function.Supplier;
+
+import org.spongepowered.asm.mixin.Final;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Shadow;
+import org.spongepowered.asm.mixin.Unique;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
+
+import net.minecraft.client.render.entity.EntityRenderDispatcher;
+import net.minecraft.client.render.entity.EntityRenderer;
+import net.minecraft.entity.Entity;
+
+import net.ornithemc.osl.entities.api.client.EntityRenderingEvents;
+
+@Mixin(EntityRenderDispatcher.class)
+public class EntityRenderDispatcherMixin {
+
+	@Shadow @Final
+	private Map<Class<? extends Entity>, EntityRenderer<? extends Entity>> renderers;
+
+	@Inject(
+		method = "<init>",
+		at = @At(
+			value = "INVOKE",
+			target = "Ljava/util/Map;values()Ljava/util/Collection;"
+		)
+	)
+	private void osl$entities$registerEntityRenderers(CallbackInfo ci) {
+		EntityRenderingEvents.REGISTER_ENTITY_RENDERERS.invoker().accept(this::register);
+	}
+
+	@Unique
+	private <T extends Entity> void register(Class<T> type, Supplier<EntityRenderer<? super T>> factory) {
+		this.renderers.put(type, factory.get());
+	}
+}
diff --git a/libraries/entities-rendering/entities-rendering-mca1.0.1_01-mc14w04b/src/main/resources/fabric.mod.json b/libraries/entities-rendering/entities-rendering-mca1.0.1_01-mc14w04b/src/main/resources/fabric.mod.json
new file mode 100644
index 00000000..497fc5e1
--- /dev/null
+++ b/libraries/entities-rendering/entities-rendering-mca1.0.1_01-mc14w04b/src/main/resources/fabric.mod.json
@@ -0,0 +1,26 @@
+{
+  "schemaVersion": 1,
+  "id": "osl-entities-rendering",
+  "version": "0.1.0+mca1.0.1_01-mc14w04b",
+  "environment": "client",
+  "mixins": [
+    "osl.entities-rendering.mixins.json"
+  ],
+  "depends": {
+    "fabricloader": "\u003e\u003d0.18.0",
+    "minecraft": "\u003e\u003d1.0.0-alpha.0.1.1 \u003c\u003d1.8-alpha.14.4.b",
+    "osl-core": "\u003e\u003d0.9.0",
+    "osl-entrypoints": "\u003e\u003d0.5.0"
+  },
+  "name": "OSL Entities Rendering",
+  "description": "Entities Rendering API and events.",
+  "authors": [
+    "OrnitheMC"
+  ],
+  "contact": {
+    "homepage": "https://ornithemc.net/",
+    "issues": "https://github.com/OrnitheMC/ornithe-standard-libraries/issues",
+    "sources": "https://github.com/OrnitheMC/ornithe-standard-libraries"
+  },
+  "license": "Apache-2.0"
+}
\ No newline at end of file
diff --git a/libraries/entities-rendering/entities-rendering-mca1.0.1_01-mc14w04b/src/main/resources/osl.entities-rendering.mixins.json b/libraries/entities-rendering/entities-rendering-mca1.0.1_01-mc14w04b/src/main/resources/osl.entities-rendering.mixins.json
new file mode 100644
index 00000000..5e8354bf
--- /dev/null
+++ b/libraries/entities-rendering/entities-rendering-mca1.0.1_01-mc14w04b/src/main/resources/osl.entities-rendering.mixins.json
@@ -0,0 +1,16 @@
+{
+	"required": true,
+	"minVersion": "0.8",
+	"package": "net.ornithemc.osl.entities.impl.mixin",
+	"compatibilityLevel": "JAVA_8",
+	"mixins": [
+	],
+	"client": [
+		"client.EntityRenderDispatcherMixin"
+	],
+	"server": [
+	],
+	"injectors": {
+		"defaultRequire": 1
+	}
+}
diff --git a/libraries/entities-rendering/gradle.properties b/libraries/entities-rendering/gradle.properties
new file mode 100644
index 00000000..87d4295c
--- /dev/null
+++ b/libraries/entities-rendering/gradle.properties
@@ -0,0 +1,6 @@
+library_id = entities-rendering
+library_name = Entities Rendering
+library_description = Entities Rendering API and events.
+library_version = 0.1.0
+
+osl_dependencies = core:0.9.0,entrypoints:0.5.0
diff --git a/libraries/entities/README.md b/libraries/entities/README.md
new file mode 100644
index 00000000..c01fa49e
--- /dev/null
+++ b/libraries/entities/README.md
@@ -0,0 +1,43 @@
+# Entities API
+
+The Entities API provides events and utilities for registering and working with entities.
+
+## Registering Custom Entity Types
+
+Entity type registration should be done in a listener to the `REGISTER_ENTITY_TYPES` event. The `EntityTypeRegistry` class provides utility methods for registering entity types.
+
+An example is shown below.
+
+```java
+package com.example;
+
+import net.ornithemc.osl.entities.api.EntityEvents;
+import net.ornithemc.osl.entrypoints.api.ModInitializer;
+
+public class ExampleInitializer implements ModInitializer {
+
+	@Override
+	public void init() {
+		EntityEvents.REGISTER_ENTITY_TYPES.register(ExampleEntityTypes::init);
+	}
+}
+```
+
+```java
+package com.example;
+
+import net.minecraft.entity.EntityType;
+import net.minecraft.entity.living.MobCategory;
+
+import net.ornithemc.osl.entities.api.EntityTypeRegistry;
+import net.ornithemc.osl.entities.api.EntityTypes;
+import net.ornithemc.osl.core.util.NamespacedIdentifiers;
+
+public final class ExampleEntityTypes {
+
+	public static final EntityType<CookieMonsterEntity> COOKIE_MONSTER = EntityTypeRegistry.register(NamespacedIdentifiers.from("example", "cookie_monster"), EntityTypes.builder(CookieMonsterEntity::new, MobCategory.MISC));
+
+	public static void init() {
+	}
+}
+```
diff --git a/libraries/entities/build.gradle b/libraries/entities/build.gradle
new file mode 100644
index 00000000..e98ba2c6
--- /dev/null
+++ b/libraries/entities/build.gradle
@@ -0,0 +1 @@
+setUpLibrary(project)
diff --git a/libraries/entities/entities-mc1.8.2-pre5-mc1.10.2/build.gradle b/libraries/entities/entities-mc1.8.2-pre5-mc1.10.2/build.gradle
new file mode 100644
index 00000000..0a350fdb
--- /dev/null
+++ b/libraries/entities/entities-mc1.8.2-pre5-mc1.10.2/build.gradle
@@ -0,0 +1 @@
+setUpModule(project)
diff --git a/libraries/entities/entities-mc1.8.2-pre5-mc1.10.2/gradle.properties b/libraries/entities/entities-mc1.8.2-pre5-mc1.10.2/gradle.properties
new file mode 100644
index 00000000..27ea8651
--- /dev/null
+++ b/libraries/entities/entities-mc1.8.2-pre5-mc1.10.2/gradle.properties
@@ -0,0 +1,4 @@
+min_mc_version = 1.8.2-pre5
+max_mc_version = 1.10.2
+
+minecraft_version = 1.8.9
diff --git a/libraries/entities/entities-mc1.8.2-pre5-mc1.10.2/src/main/java/net/ornithemc/osl/entities/api/EntityEvents.java b/libraries/entities/entities-mc1.8.2-pre5-mc1.10.2/src/main/java/net/ornithemc/osl/entities/api/EntityEvents.java
new file mode 100644
index 00000000..d7c80c74
--- /dev/null
+++ b/libraries/entities/entities-mc1.8.2-pre5-mc1.10.2/src/main/java/net/ornithemc/osl/entities/api/EntityEvents.java
@@ -0,0 +1,34 @@
+package net.ornithemc.osl.entities.api;
+
+import net.ornithemc.osl.core.api.events.Event;
+
+/**
+ * Events related to the entities lifecycle.
+ */
+public final class EntityEvents {
+
+	/**
+	 * This event is invoked upon game start-up, after Vanilla entity registration is finished.
+	 * 
+	 * <p>
+	 * Custom entity type registration should be done in a listener of this event.
+	 * Helper methods for registering entity types can be found in the {@linkplain
+	 * EntityTypeRegistry} class.
+	 * 
+	 * <p>
+	 * Listeners to this event should be registered in your mod's entrypoint,
+	 * and can be done as follows:
+	 * 
+	 * <pre>
+	 * {@code
+	 * EntityEvents.REGISTER_ENTITY_TYPES.register(() -> {
+	 * 	EntityTypeRegistry.register(NamespacedIdentifiers.from("example", "cookie_monster"), CookieMonsterEntity.class);
+	 * });
+	 * }
+	 * </pre>
+	 * 
+	 * @see EntityTypeRegistry
+	 */
+	public static final Event<Runnable> REGISTER_ENTITY_TYPES = Event.runnable();
+
+}
diff --git a/libraries/entities/entities-mc1.8.2-pre5-mc1.10.2/src/main/java/net/ornithemc/osl/entities/api/EntityTypeRegistry.java b/libraries/entities/entities-mc1.8.2-pre5-mc1.10.2/src/main/java/net/ornithemc/osl/entities/api/EntityTypeRegistry.java
new file mode 100644
index 00000000..174ac7f3
--- /dev/null
+++ b/libraries/entities/entities-mc1.8.2-pre5-mc1.10.2/src/main/java/net/ornithemc/osl/entities/api/EntityTypeRegistry.java
@@ -0,0 +1,148 @@
+package net.ornithemc.osl.entities.api;
+
+import java.util.Set;
+
+import net.minecraft.entity.Entity;
+
+import net.ornithemc.osl.core.api.util.NamespacedIdentifier;
+import net.ornithemc.osl.entities.impl.EntityTypeRegistryImpl;
+import net.ornithemc.osl.registries.api.registry.Registry;
+import net.ornithemc.osl.registries.api.registry.ResourceKey;
+
+/**
+ * Public access to the Entity Types registry.
+ */
+public final class EntityTypeRegistry {
+
+	public static final Registry<Class<? extends Entity>> REGISTRY = EntityTypeRegistryImpl.REGISTRY;
+
+	/**
+	 * @return the numerical ID assigned to the given entity type.
+	 */
+	public static int getId(Class<? extends Entity> type) {
+		return EntityTypeRegistryImpl.getId(type);
+	}
+
+	/**
+	 * @return the namespaced ID assigned to the given entity type.
+	 */
+	public static NamespacedIdentifier getIdentifier(Class<? extends Entity> type) {
+		return EntityTypeRegistryImpl.getIdentifier(type);
+	}
+
+	/**
+	 * @return the resource key assigned to the given entity type.
+	 */
+	public static ResourceKey<Class<? extends Entity>> getKey(Class<? extends Entity> type) {
+		return EntityTypeRegistryImpl.getKey(type);
+	}
+
+	/**
+	 * @return the legacy {@code String} key assigned to the given entity type.
+	 */
+	public static String getLegacyKey(Class<? extends Entity> type) {
+		return EntityTypeRegistryImpl.getLegacyKey(type);
+	}
+
+	/**
+	 * @return the entity type mapped to the given numerical ID.
+	 */
+	public static Class<? extends Entity> getEntityType(int id) {
+		return EntityTypeRegistryImpl.getEntityType(id);
+	}
+
+	/**
+	 * @return the entity type mapped to the given namespaced ID.
+	 */
+	public static Class<? extends Entity> getEntityType(NamespacedIdentifier identifier) {
+		return EntityTypeRegistryImpl.getEntityType(identifier);
+	}
+
+	/**
+	 * @return the entity type mapped to the given resource key.
+	 */
+	public static Class<? extends Entity> getEntityType(ResourceKey<Class<? extends Entity>> key) {
+		return EntityTypeRegistryImpl.getEntityType(key);
+	}
+
+	/**
+	 * @return the entity type mapped to the given legacy {@code String} key.
+	 */
+	public static Class<? extends Entity> getEntityType(String legacyKey) {
+		return EntityTypeRegistryImpl.getEntityType(legacyKey);
+	}
+
+	/**
+	 * @return a set containing all namespaced IDs in the registry.
+	 */
+	public static Set<NamespacedIdentifier> identifierSet() {
+		return EntityTypeRegistryImpl.identifierSet();
+	}
+
+	/**
+	 * @return a set containing all resource keys in the registry.
+	 */
+	public static Set<ResourceKey<Class<? extends Entity>>> keySet() {
+		return EntityTypeRegistryImpl.keySet();
+	}
+
+	/**
+	 * @return a set containing all legacy {@code String} keys in the registry.
+	 */
+	public static Set<String> legacyKeySet() {
+		return EntityTypeRegistryImpl.legacyKeySet();
+	}
+
+	/**
+	 * @param <T>        the entity type.
+	 * @param identifier the namespaced ID of the entity type.
+	 * @param type       the entity type to register.
+	 * @return the registered entity type.
+	 */
+	public static <T extends Entity> Class<T> register(NamespacedIdentifier identifier, Class<T> type) {
+		return EntityTypeRegistryImpl.register(identifier, type);
+	}
+
+	/**
+	 * @param <T>   the entity type.
+	 * @param key   the resource key of the entity type.
+	 * @param type  the entity type to register.
+	 * @return the registered entity type.
+	 */
+	public static <T extends Entity> Class<T> register(ResourceKey<Class<? extends Entity>> key, Class<T> type) {
+		return EntityTypeRegistryImpl.register(key, type);
+	}
+
+	/**
+	 * Registers spawn egg data for the specified entity type.
+	 * 
+	 * @param identifier the identifier of the entity type for which to register the spawn egg data.
+	 * @param baseColor  the base color of the spawn egg.
+	 * @param spotsColor the color of the spots on the spawn egg.
+	 */
+	public static void registerSpawnEggData(NamespacedIdentifier identifier, int baseColor, int spotsColor) {
+		EntityTypeRegistryImpl.registerSpawnEggData(identifier, baseColor, spotsColor);
+	}
+
+	/**
+	 * Registers spawn egg data for the specified entity type.
+	 * 
+	 * @param key        the resource key of the entity type for which to register the spawn egg data.
+	 * @param baseColor  the base color of the spawn egg.
+	 * @param spotsColor the color of the spots on the spawn egg.
+	 */
+	public static void registerSpawnEggData(ResourceKey<Class<? extends Entity>> key, int baseColor, int spotsColor) {
+		EntityTypeRegistryImpl.registerSpawnEggData(key, baseColor, spotsColor);
+	}
+
+	/**
+	 * Registers spawn egg data for the specified entity type.
+	 * 
+	 * @param type       the entity type for which to register the spawn egg data.
+	 * @param baseColor  the base color of the spawn egg.
+	 * @param spotsColor the color of the spots on the spawn egg.
+	 */
+	public static void registerSpawnEggData(Class<? extends Entity> type, int baseColor, int spotsColor) {
+		EntityTypeRegistryImpl.registerSpawnEggData(type, baseColor, spotsColor);
+	}
+}
diff --git a/libraries/entities/entities-mc1.8.2-pre5-mc1.10.2/src/main/java/net/ornithemc/osl/entities/impl/EntitiesMixinPlugin.java b/libraries/entities/entities-mc1.8.2-pre5-mc1.10.2/src/main/java/net/ornithemc/osl/entities/impl/EntitiesMixinPlugin.java
new file mode 100644
index 00000000..f9fdef4d
--- /dev/null
+++ b/libraries/entities/entities-mc1.8.2-pre5-mc1.10.2/src/main/java/net/ornithemc/osl/entities/impl/EntitiesMixinPlugin.java
@@ -0,0 +1,56 @@
+package net.ornithemc.osl.entities.impl;
+
+import java.util.List;
+import java.util.Set;
+
+import org.objectweb.asm.tree.ClassNode;
+
+import org.spongepowered.asm.mixin.extensibility.IMixinConfigPlugin;
+import org.spongepowered.asm.mixin.extensibility.IMixinInfo;
+
+import net.ornithemc.osl.core.impl.util.MinecraftVersion;
+
+public class EntitiesMixinPlugin implements IMixinConfigPlugin {
+
+	public static final boolean SPAWN_EGGS_BY_ID = MinecraftVersion.resolve().compareTo("15w33a") < 0;
+
+	@Override
+	public void onLoad(String mixinPackage) {
+	}
+
+	@Override
+	public String getRefMapperConfig() {
+		return null;
+	}
+
+	@Override
+	public boolean shouldApplyMixin(String targetClassName, String mixinClassName) {
+		if ("net.ornithemc.osl.entities.impl.mixin.common.EntitiesMixin_15w32c".equals(mixinClassName)
+			|| "net.ornithemc.osl.entities.impl.mixin.common.SpawnEggDataAccessOld".equals(mixinClassName)) {
+			return SPAWN_EGGS_BY_ID;
+		}
+		if ("net.ornithemc.osl.entities.impl.mixin.common.EntitiesMixin_15w33a".equals(mixinClassName)
+			|| "net.ornithemc.osl.entities.impl.mixin.common.SpawnEggDataAccessNew".equals(mixinClassName)) {
+			return !SPAWN_EGGS_BY_ID;
+		}
+
+		return true;
+	}
+
+	@Override
+	public void acceptTargets(Set<String> myTargets, Set<String> otherTargets) {
+	}
+
+	@Override
+	public List<String> getMixins() {
+		return null;
+	}
+
+	@Override
+	public void preApply(String targetClassName, ClassNode targetClass, String mixinClassName, IMixinInfo mixinInfo) {
+	}
+
+	@Override
+	public void postApply(String targetClassName, ClassNode targetClass, String mixinClassName, IMixinInfo mixinInfo) {
+	}
+}
diff --git a/libraries/entities/entities-mc1.8.2-pre5-mc1.10.2/src/main/java/net/ornithemc/osl/entities/impl/EntityTypeRegistryImpl.java b/libraries/entities/entities-mc1.8.2-pre5-mc1.10.2/src/main/java/net/ornithemc/osl/entities/impl/EntityTypeRegistryImpl.java
new file mode 100644
index 00000000..da39bb37
--- /dev/null
+++ b/libraries/entities/entities-mc1.8.2-pre5-mc1.10.2/src/main/java/net/ornithemc/osl/entities/impl/EntityTypeRegistryImpl.java
@@ -0,0 +1,113 @@
+package net.ornithemc.osl.entities.impl;
+
+import java.util.Set;
+
+import net.minecraft.entity.Entities;
+import net.minecraft.entity.Entity;
+
+import net.ornithemc.osl.core.api.util.NamespacedIdentifier;
+import net.ornithemc.osl.entities.api.EntityEvents;
+import net.ornithemc.osl.registries.api.registry.Registry;
+import net.ornithemc.osl.registries.api.registry.RegistryKeys;
+import net.ornithemc.osl.registries.api.registry.ResourceKey;
+import net.ornithemc.osl.registries.api.registry.SyncedRegistries;
+import net.ornithemc.osl.registries.impl.registry.RegistriesImpl;
+
+public final class EntityTypeRegistryImpl {
+
+	public static final WrappedEntityTypeRegistry REGISTRY = RegistriesImpl.register(RegistryKeys.ENTITY_TYPE, new WrappedEntityTypeRegistry(RegistryKeys.ENTITY_TYPE.identifier()), () -> Entities.KEY_TO_TYPE.getClass());
+	/*
+	 * Entities.SPAWN_EGG_DATA changes key type from Integer to String in 15w33a so we can't reference it directly.
+	 */
+	public static SpawnEggDataRegistry SPAWN_EGG_DATA_REGISTRY;
+
+	private static boolean locked = true;
+
+	public static int getId(Class<? extends Entity> type) {
+		return REGISTRY.getId(type);
+	}
+
+	public static NamespacedIdentifier getIdentifier(Class<? extends Entity> type) {
+		return REGISTRY.getIdentifier(type);
+	}
+
+	public static ResourceKey<Class<? extends Entity>> getKey(Class<? extends Entity> type) {
+		return REGISTRY.getKey(type);
+	}
+
+	public static String getLegacyKey(Class<? extends Entity> type) {
+		return REGISTRY.getLegacyKey(type);
+	}
+
+	public static Class<? extends Entity> getEntityType(int id) {
+		return REGISTRY.get(id);
+	}
+
+	public static Class<? extends Entity> getEntityType(NamespacedIdentifier identifier) {
+		return REGISTRY.get(identifier);
+	}
+
+	public static Class<? extends Entity> getEntityType(ResourceKey<Class<? extends Entity>> key) {
+		return REGISTRY.get(key);
+	}
+
+	public static Class<? extends Entity> getEntityType(String legacyKey) {
+		return REGISTRY.get(legacyKey);
+	}
+
+	public static Set<NamespacedIdentifier> identifierSet() {
+		return REGISTRY.identifierSet();
+	}
+
+	public static Set<ResourceKey<Class<? extends Entity>>> keySet() {
+		return REGISTRY.keySet();
+	}
+
+	public static Set<String> legacyKeySet() {
+		return REGISTRY.legacyKeySet();
+	}
+
+	public static <T extends Entity> Class<T> register(NamespacedIdentifier identifier, Class<T> type) {
+		if (locked) {
+			throw new IllegalStateException("register called too early: registry locked!");
+		} else {
+			return Registry.register(REGISTRY, identifier, type);
+		}
+	}
+
+	public static <T extends Entity> Class<T> register(ResourceKey<Class<? extends Entity>> key, Class<T> type) {
+		if (locked) {
+			throw new IllegalStateException("register called too early: registry locked!");
+		} else {
+			return Registry.register(REGISTRY, key, type);
+		}
+	}
+
+	public static void registerSpawnEggData(NamespacedIdentifier identifier, int baseColor, int spotsColor) {
+		registerSpawnEggData(getEntityType(identifier), baseColor, spotsColor);
+	}
+
+	public static void registerSpawnEggData(ResourceKey<Class<? extends Entity>> key, int baseColor, int spotsColor) {
+		registerSpawnEggData(getEntityType(key), baseColor, spotsColor);
+	}
+
+	public static void registerSpawnEggData(Class<? extends Entity> type, int baseColor, int spotsColor) {
+		if (locked) {
+			throw new IllegalStateException("register called too early: registry locked!");
+		} else {
+			SPAWN_EGG_DATA_REGISTRY.register(type, baseColor, spotsColor);
+		}
+	}
+
+	public static void init() {
+		SyncedRegistries.register(RegistryKeys.ENTITY_TYPE);
+	}
+
+	public static void unlock() {
+		locked = false;
+	}
+
+	public static void registerEntityTypes() {
+		EntityEvents.REGISTER_ENTITY_TYPES.invoker().run();
+	}
+}
diff --git a/libraries/entities/entities-mc1.8.2-pre5-mc1.10.2/src/main/java/net/ornithemc/osl/entities/impl/SpawnEggDataRegistry.java b/libraries/entities/entities-mc1.8.2-pre5-mc1.10.2/src/main/java/net/ornithemc/osl/entities/impl/SpawnEggDataRegistry.java
new file mode 100644
index 00000000..3cac80d8
--- /dev/null
+++ b/libraries/entities/entities-mc1.8.2-pre5-mc1.10.2/src/main/java/net/ornithemc/osl/entities/impl/SpawnEggDataRegistry.java
@@ -0,0 +1,10 @@
+package net.ornithemc.osl.entities.impl;
+
+import net.minecraft.entity.Entity;
+
+@FunctionalInterface
+public interface SpawnEggDataRegistry {
+
+	void register(Class<? extends Entity> type, int baseColor, int spotsColor);
+
+}
diff --git a/libraries/entities/entities-mc1.8.2-pre5-mc1.10.2/src/main/java/net/ornithemc/osl/entities/impl/VanillaEntityTypes.java b/libraries/entities/entities-mc1.8.2-pre5-mc1.10.2/src/main/java/net/ornithemc/osl/entities/impl/VanillaEntityTypes.java
new file mode 100644
index 00000000..b0a5bebc
--- /dev/null
+++ b/libraries/entities/entities-mc1.8.2-pre5-mc1.10.2/src/main/java/net/ornithemc/osl/entities/impl/VanillaEntityTypes.java
@@ -0,0 +1,80 @@
+package net.ornithemc.osl.entities.impl;
+
+import com.google.common.collect.BiMap;
+import com.google.common.collect.HashBiMap;
+
+final class VanillaEntityTypes {
+
+	static final BiMap<String, String> IDENTIFIERS = HashBiMap.create();
+
+	static {
+		IDENTIFIERS.put("Item", "item");
+		IDENTIFIERS.put("XPOrb", "xp_orb");
+		IDENTIFIERS.put("AreaEffectCloud", "area_effect_cloud");
+		IDENTIFIERS.put("ThrownEgg", "egg");
+		IDENTIFIERS.put("LeashKnot", "leash_knot");
+		IDENTIFIERS.put("Painting", "painting");
+		IDENTIFIERS.put("Arrow", "arrow");
+		IDENTIFIERS.put("Snowball", "snowball");
+		IDENTIFIERS.put("Fireball", "fireball");
+		IDENTIFIERS.put("SmallFireball", "small_fireball");
+		IDENTIFIERS.put("ThrownEnderPearl", "ender_pearl");
+		IDENTIFIERS.put("EyeOfEnderSignal", "eye_of_ender_signal");
+		IDENTIFIERS.put("ThrowPotion", "potion");
+		IDENTIFIERS.put("ThrownExpBottle", "xp_bottle");
+		IDENTIFIERS.put("ItemFrame", "item_frame");
+		IDENTIFIERS.put("WitherSkull", "wither_skull");
+		IDENTIFIERS.put("PrimedTNT", "tnt");
+		IDENTIFIERS.put("FallingSand", "falling_block");
+		IDENTIFIERS.put("FireworksRocketEntity", "fireworks_rocket");
+		IDENTIFIERS.put("SpectralArrow", "spectral_arrow");
+		IDENTIFIERS.put("ShulkerBullet", "shulker_bullet");
+		IDENTIFIERS.put("DragonFireball", "dragon_fireball");
+		IDENTIFIERS.put("ArmorStand", "armor_stand");
+		IDENTIFIERS.put("Boat", "boat");
+		IDENTIFIERS.put("MinecartRideable", "minecart");
+		IDENTIFIERS.put("MinecartChest", "chest_minecart");
+		IDENTIFIERS.put("MinecartFurnace", "furnace_minecart");
+		IDENTIFIERS.put("MinecartTNT", "tnt_minecart");
+		IDENTIFIERS.put("MinecartSpawner", "spawner_minecart");
+		IDENTIFIERS.put("MinecartHopper", "hopper_minecart");
+		IDENTIFIERS.put("MinecartCommandBlock", "commandblock_minecart");
+		IDENTIFIERS.put("Mob", "mob");
+		IDENTIFIERS.put("Monster", "monster");
+		IDENTIFIERS.put("Creeper", "creeper");
+		IDENTIFIERS.put("Skeleton", "skeleton");
+		IDENTIFIERS.put("Spider", "spider");
+		IDENTIFIERS.put("Giant", "giant");
+		IDENTIFIERS.put("Zombie", "zombie");
+		IDENTIFIERS.put("Slime", "slime");
+		IDENTIFIERS.put("Ghast", "ghast");
+		IDENTIFIERS.put("PigZombie", "zombie_pigman");
+		IDENTIFIERS.put("Enderman", "enderman");
+		IDENTIFIERS.put("CaveSpider", "cave_spider");
+		IDENTIFIERS.put("Silverfish", "silverfish");
+		IDENTIFIERS.put("Blaze", "blaze");
+		IDENTIFIERS.put("LavaSlime", "magma_cube");
+		IDENTIFIERS.put("EnderDragon", "ender_dragon");
+		IDENTIFIERS.put("WitherBoss", "wither");
+		IDENTIFIERS.put("Bat", "bat");
+		IDENTIFIERS.put("Witch", "witch");
+		IDENTIFIERS.put("Endermite", "endermite");
+		IDENTIFIERS.put("Guardian", "guardian");
+		IDENTIFIERS.put("Shulker", "shulker");
+		IDENTIFIERS.put("Pig", "pig");
+		IDENTIFIERS.put("Sheep", "sheep");
+		IDENTIFIERS.put("Cow", "cow");
+		IDENTIFIERS.put("Chicken", "chicken");
+		IDENTIFIERS.put("Squid", "squid");
+		IDENTIFIERS.put("Wolf", "wolf");
+		IDENTIFIERS.put("MushroomCow", "mooshroom");
+		IDENTIFIERS.put("SnowMan", "snowman");
+		IDENTIFIERS.put("Ozelot", "ocelot");
+		IDENTIFIERS.put("VillagerGolem", "villager_golem");
+		IDENTIFIERS.put("EntityHorse", "horse");
+		IDENTIFIERS.put("Rabbit", "rabbit");
+		IDENTIFIERS.put("PolarBear", "polar_bear");
+		IDENTIFIERS.put("Villager", "villager");
+		IDENTIFIERS.put("EnderCrystal", "ender_crystal");
+	}
+}
diff --git a/libraries/entities/entities-mc1.8.2-pre5-mc1.10.2/src/main/java/net/ornithemc/osl/entities/impl/WrappedEntityTypeRegistry.java b/libraries/entities/entities-mc1.8.2-pre5-mc1.10.2/src/main/java/net/ornithemc/osl/entities/impl/WrappedEntityTypeRegistry.java
new file mode 100644
index 00000000..c6643492
--- /dev/null
+++ b/libraries/entities/entities-mc1.8.2-pre5-mc1.10.2/src/main/java/net/ornithemc/osl/entities/impl/WrappedEntityTypeRegistry.java
@@ -0,0 +1,125 @@
+package net.ornithemc.osl.entities.impl;
+
+import java.util.Set;
+
+import com.google.common.collect.BiMap;
+import com.google.common.collect.HashBiMap;
+
+import net.minecraft.entity.Entities;
+import net.minecraft.entity.Entity;
+
+import net.ornithemc.osl.core.api.util.NamespacedIdentifier;
+import net.ornithemc.osl.core.api.util.NamespacedIdentifiers;
+import net.ornithemc.osl.registries.api.registry.ResourceKey;
+import net.ornithemc.osl.registries.api.registry.ResourceKeys;
+import net.ornithemc.osl.registries.impl.registry.SimpleRegistry;
+
+public class WrappedEntityTypeRegistry extends SimpleRegistry<Class<? extends Entity>> {
+
+	private final BiMap<NamespacedIdentifier, String> legacyKeys = HashBiMap.create();
+
+	private boolean skipEntitiesRegister;
+
+	WrappedEntityTypeRegistry(NamespacedIdentifier identifier) {
+		super(identifier);
+	}
+
+	public void register(int id, String legacyKey, Class<? extends Entity> type) {
+		NamespacedIdentifier identifier = this.constructIdentifier(legacyKey);
+		ResourceKey<Class<? extends Entity>> key = ResourceKeys.from(this.identifier(), identifier);
+
+		this.skipEntitiesRegister = true;
+		this.register(id, key, type);
+		this.skipEntitiesRegister = false;
+	}
+
+	@Override
+	public <V extends Class<? extends Entity>> V register(int id, ResourceKey<Class<? extends Entity>> key, V type) {
+		type = super.register(id, key, type);
+
+		if (!this.skipEntitiesRegister) {
+			NamespacedIdentifier identifier = key.identifier();
+			String legacyKey = this.constructLegacyKey(identifier);
+
+			if (Entities.KEY_TO_TYPE.containsKey(legacyKey)) {
+				throw new IllegalStateException("Duplicate legacy Entity type key " + legacyKey);
+			}
+
+			Entities.KEY_TO_TYPE.put(legacyKey, type);
+			Entities.TYPE_TO_KEY.put(type, legacyKey);
+			Entities.ID_TO_TYPE.put(id, type);
+			Entities.TYPE_TO_ID.put(type, id);
+			Entities.KEY_TO_ID.put(legacyKey, id);
+		}
+
+		return type;
+	}
+
+	private String constructLegacyKey(NamespacedIdentifier identifier) {
+		return this.legacyKeys.computeIfAbsent(identifier, key -> {
+			if (identifier.namespace().equals(NamespacedIdentifiers.DEFAULT_NAMESPACE)) {
+				String legacyKey = VanillaEntityTypes.IDENTIFIERS.inverse().get(identifier.identifier());
+
+				if (legacyKey != null) {
+					return legacyKey;
+				}
+			}
+
+			return identifier.toString();
+		});
+	}
+
+	private NamespacedIdentifier constructIdentifier(String legacyKey) {
+		return this.legacyKeys.inverse().computeIfAbsent(legacyKey, key -> {
+			String identifier = VanillaEntityTypes.IDENTIFIERS.get(legacyKey);
+
+			if (identifier != null) {
+				return NamespacedIdentifiers.from(identifier);
+			}
+
+			StringBuilder sb = new StringBuilder();
+
+			// convert PascalCase to snake_case
+			for (int i = 0; i < legacyKey.length(); i++) {
+				char chr = legacyKey.charAt(i);
+
+				if (Character.isUpperCase(chr)) {
+					chr = Character.toLowerCase(chr);
+
+					if (i != 0) {
+						sb.append('_');
+					}
+				}
+
+				sb.append(chr);
+			}
+
+			return NamespacedIdentifiers.from(sb.toString());
+		});
+	}
+
+	public Class<? extends Entity> get(String legacyKey) {
+		NamespacedIdentifier identifier = this.legacyKeys.inverse().get(legacyKey);
+		return identifier == null ? null : this.get(identifier);
+	}
+
+	public String getLegacyKey(Class<? extends Entity> type) {
+		NamespacedIdentifier identifier = this.getIdentifier(type);
+		return identifier == null ? null : this.legacyKeys.get(identifier);
+	}
+
+	public Set<String> legacyKeySet() {
+		return this.legacyKeys.values();
+	}
+
+	@Override
+	public void clear() {
+		super.clear();
+
+		Entities.KEY_TO_TYPE.clear();
+		Entities.TYPE_TO_KEY.clear();
+		Entities.ID_TO_TYPE.clear();
+		Entities.TYPE_TO_ID.clear();
+		Entities.KEY_TO_ID.clear();
+	}
+}
diff --git a/libraries/entities/entities-mc1.8.2-pre5-mc1.10.2/src/main/java/net/ornithemc/osl/entities/impl/entity/SpawnEggDataMapper.java b/libraries/entities/entities-mc1.8.2-pre5-mc1.10.2/src/main/java/net/ornithemc/osl/entities/impl/entity/SpawnEggDataMapper.java
new file mode 100644
index 00000000..2bef3a81
--- /dev/null
+++ b/libraries/entities/entities-mc1.8.2-pre5-mc1.10.2/src/main/java/net/ornithemc/osl/entities/impl/entity/SpawnEggDataMapper.java
@@ -0,0 +1,68 @@
+package net.ornithemc.osl.entities.impl.entity;
+
+import java.util.Collections;
+import java.util.IdentityHashMap;
+import java.util.Map;
+import java.util.Set;
+
+import it.unimi.dsi.fastutil.ints.Int2IntFunction;
+
+import net.minecraft.entity.Entities.SpawnEggData;
+
+import net.ornithemc.osl.entities.impl.mixin.common.SpawnEggDataAccessOld;
+import net.ornithemc.osl.registries.api.registry.sync.IdMapper;
+import net.ornithemc.osl.registries.api.registry.sync.RegistryMappings;
+
+public class SpawnEggDataMapper implements IdMapper {
+
+	public static SpawnEggDataMapper of(Map<Integer, SpawnEggData> spawnEggData) {
+		return new SpawnEggDataMapper(spawnEggData);
+	}
+
+	private final Map<Integer, SpawnEggData> spawnEggData;
+	private final Set<SpawnEggData> missing;
+
+	private boolean applied;
+
+	private SpawnEggDataMapper(Map<Integer, SpawnEggData> spawnEggData) {
+		this.spawnEggData = spawnEggData;
+		this.missing = Collections.newSetFromMap(new IdentityHashMap<>());
+	}
+
+	@Override
+	public void apply(RegistryMappings mappings) {
+		this.missing.clear();
+		this.fixSpawnEggData(mappings::remap, true);
+
+		this.applied = true;
+	}
+
+	@Override
+	public void undo(RegistryMappings mappings) {
+		if (this.applied) {
+			this.fixSpawnEggData(mappings::unmap, false);
+			this.missing.clear();
+		}
+
+		this.applied = false;
+	}
+
+	private void fixSpawnEggData(Int2IntFunction mapper, boolean storeMissing) {
+		for (SpawnEggData spawnEgg : this.spawnEggData.values()) {
+			if (this.missing.contains(spawnEgg)) {
+				continue;
+			}
+
+			SpawnEggDataAccessOld spawnEggAccess = (SpawnEggDataAccessOld) spawnEgg;
+
+			int oldId = spawnEgg.id;
+			int newId = mapper.applyAsInt(oldId);
+
+			if (newId >= 0) {
+				spawnEggAccess.setId(newId);
+			} else if (storeMissing) {
+				this.missing.add(spawnEgg);
+			}
+		}
+	}
+}
diff --git a/libraries/entities/entities-mc1.8.2-pre5-mc1.10.2/src/main/java/net/ornithemc/osl/entities/impl/mixin/common/EntitiesMixin.java b/libraries/entities/entities-mc1.8.2-pre5-mc1.10.2/src/main/java/net/ornithemc/osl/entities/impl/mixin/common/EntitiesMixin.java
new file mode 100644
index 00000000..35aef159
--- /dev/null
+++ b/libraries/entities/entities-mc1.8.2-pre5-mc1.10.2/src/main/java/net/ornithemc/osl/entities/impl/mixin/common/EntitiesMixin.java
@@ -0,0 +1,45 @@
+package net.ornithemc.osl.entities.impl.mixin.common;
+
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
+
+import net.minecraft.entity.Entities;
+import net.minecraft.entity.Entity;
+
+import net.ornithemc.osl.entities.impl.EntityTypeRegistryImpl;
+
+@Mixin(Entities.class)
+public class EntitiesMixin {
+
+	@Inject(
+		method = "register",
+		at = @At(
+			value = "TAIL"
+		)
+	)
+	private static void osl$entities$register(Class<? extends Entity> type, String legacyKey, int id, CallbackInfo ci) {
+		EntityTypeRegistryImpl.REGISTRY.register(id, legacyKey, type);
+	}
+
+	@Inject(
+		method = "<clinit>",
+		at = @At(
+			value = "HEAD"
+		)
+	)
+	private static void osl$entities$unlockEntityTypeRegistry(CallbackInfo ci) {
+		EntityTypeRegistryImpl.unlock();
+	}
+
+	@Inject(
+		method = "<clinit>",
+		at = @At(
+			value = "TAIL"
+		)
+	)
+	private static void osl$entities$registerEntityTypes(CallbackInfo ci) {
+		EntityTypeRegistryImpl.registerEntityTypes();
+	}
+}
diff --git a/libraries/entities/entities-mc1.8.2-pre5-mc1.10.2/src/main/java/net/ornithemc/osl/entities/impl/mixin/common/EntitiesMixin_15w32c.java b/libraries/entities/entities-mc1.8.2-pre5-mc1.10.2/src/main/java/net/ornithemc/osl/entities/impl/mixin/common/EntitiesMixin_15w32c.java
new file mode 100644
index 00000000..b4b21d83
--- /dev/null
+++ b/libraries/entities/entities-mc1.8.2-pre5-mc1.10.2/src/main/java/net/ornithemc/osl/entities/impl/mixin/common/EntitiesMixin_15w32c.java
@@ -0,0 +1,63 @@
+package net.ornithemc.osl.entities.impl.mixin.common;
+
+import java.util.Map;
+
+import org.objectweb.asm.Opcodes;
+
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Shadow;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.At.Shift;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
+
+import net.minecraft.entity.Entities;
+import net.minecraft.entity.Entities.SpawnEggData;
+
+import net.ornithemc.osl.core.api.util.NamespacedIdentifiers;
+import net.ornithemc.osl.entities.api.EntityTypeRegistry;
+import net.ornithemc.osl.entities.impl.EntityTypeRegistryImpl;
+import net.ornithemc.osl.entities.impl.entity.SpawnEggDataMapper;
+import net.ornithemc.osl.registries.api.registry.RegistryKeys;
+import net.ornithemc.osl.registries.api.registry.SyncedRegistries;
+
+@Mixin(Entities.class)
+public class EntitiesMixin_15w32c {
+
+	@Shadow
+	public static Map<Integer, SpawnEggData> SPAWN_EGG_DATA;
+
+	@Inject(
+		method = "<clinit>",
+		at = @At(
+			value = "FIELD",
+			target = "Lnet/minecraft/entity/Entities;SPAWN_EGG_DATA:Ljava/util/Map;",
+			opcode = Opcodes.PUTSTATIC,
+			shift = Shift.AFTER
+		)
+	)
+	private static void osl$entities$registerSpawnEggDataRegistry(CallbackInfo ci) {
+		EntityTypeRegistryImpl.SPAWN_EGG_DATA_REGISTRY = (type, baseColor, spotsColor) -> {
+			int id = EntityTypeRegistry.getId(type);
+
+			if (id < 0) {
+				throw new IllegalArgumentException("Entity type " + type.getSimpleName() + " is not registered!");
+			}
+			if (!SPAWN_EGG_DATA.containsKey(id)) {
+				throw new IllegalArgumentException("Duplicate entity type ID " + id + " in spawn egg data registry!");
+			}
+
+			SPAWN_EGG_DATA.put(id, new SpawnEggData(id, baseColor, spotsColor));
+		};
+	}
+
+	@Inject(
+		method = "<clinit>",
+		at = @At(
+			value = "TAIL"
+		)
+	)
+	private static void osl$entities$registerSpawnEggDataMapper(CallbackInfo ci) {
+		SyncedRegistries.registerMapper(RegistryKeys.ENTITY_TYPE, NamespacedIdentifiers.from("entity_type/spawn_egg_data"), SpawnEggDataMapper.of(SPAWN_EGG_DATA));
+	}
+}
diff --git a/libraries/entities/entities-mc1.8.2-pre5-mc1.10.2/src/main/java/net/ornithemc/osl/entities/impl/mixin/common/EntitiesMixin_15w33a.java b/libraries/entities/entities-mc1.8.2-pre5-mc1.10.2/src/main/java/net/ornithemc/osl/entities/impl/mixin/common/EntitiesMixin_15w33a.java
new file mode 100644
index 00000000..6b9f9695
--- /dev/null
+++ b/libraries/entities/entities-mc1.8.2-pre5-mc1.10.2/src/main/java/net/ornithemc/osl/entities/impl/mixin/common/EntitiesMixin_15w33a.java
@@ -0,0 +1,49 @@
+package net.ornithemc.osl.entities.impl.mixin.common;
+
+import java.util.Map;
+
+import org.objectweb.asm.Opcodes;
+
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Shadow;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.At.Shift;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
+
+import net.minecraft.entity.Entities;
+import net.minecraft.entity.Entities.SpawnEggData;
+
+import net.ornithemc.osl.entities.api.EntityTypeRegistry;
+import net.ornithemc.osl.entities.impl.EntityTypeRegistryImpl;
+
+@Mixin(Entities.class)
+public class EntitiesMixin_15w33a {
+
+	@Shadow
+	public static Map<String, SpawnEggData> SPAWN_EGG_DATA;
+
+	@Inject(
+		method = "<clinit>",
+		at = @At(
+			value = "FIELD",
+			target = "Lnet/minecraft/entity/Entities;SPAWN_EGG_DATA:Ljava/util/Map;",
+			opcode = Opcodes.PUTSTATIC,
+			shift = Shift.AFTER
+		)
+	)
+	private static void osl$entities$registerSpawnEggDataRegistry(CallbackInfo ci) {
+		EntityTypeRegistryImpl.SPAWN_EGG_DATA_REGISTRY = (type, baseColor, spotsColor) -> {
+			String legacyKey = EntityTypeRegistry.getLegacyKey(type);
+
+			if (legacyKey == null) {
+				throw new IllegalArgumentException("Entity type " + type.getSimpleName() + " is not registered!");
+			}
+			if (!SPAWN_EGG_DATA.containsKey(legacyKey)) {
+				throw new IllegalArgumentException("Duplicate entity type legacy key " + legacyKey + " in spawn egg data registry!");
+			}
+
+			SPAWN_EGG_DATA.put(legacyKey, SpawnEggDataAccessNew.of(legacyKey, baseColor, spotsColor));
+		};
+	}
+}
diff --git a/libraries/entities/entities-mc1.8.2-pre5-mc1.10.2/src/main/java/net/ornithemc/osl/entities/impl/mixin/common/SpawnEggDataAccessNew.java b/libraries/entities/entities-mc1.8.2-pre5-mc1.10.2/src/main/java/net/ornithemc/osl/entities/impl/mixin/common/SpawnEggDataAccessNew.java
new file mode 100644
index 00000000..1299e82f
--- /dev/null
+++ b/libraries/entities/entities-mc1.8.2-pre5-mc1.10.2/src/main/java/net/ornithemc/osl/entities/impl/mixin/common/SpawnEggDataAccessNew.java
@@ -0,0 +1,15 @@
+package net.ornithemc.osl.entities.impl.mixin.common;
+
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.gen.Invoker;
+
+import net.minecraft.entity.Entities.SpawnEggData;
+
+@Mixin(SpawnEggData.class)
+public interface SpawnEggDataAccessNew {
+
+	@Invoker("<init>")
+	static SpawnEggData of(String legacyKey, int baseColor, int spotsColor) {
+		throw new UnsupportedOperationException();
+	}
+}
diff --git a/libraries/entities/entities-mc1.8.2-pre5-mc1.10.2/src/main/java/net/ornithemc/osl/entities/impl/mixin/common/SpawnEggDataAccessOld.java b/libraries/entities/entities-mc1.8.2-pre5-mc1.10.2/src/main/java/net/ornithemc/osl/entities/impl/mixin/common/SpawnEggDataAccessOld.java
new file mode 100644
index 00000000..b0946ed0
--- /dev/null
+++ b/libraries/entities/entities-mc1.8.2-pre5-mc1.10.2/src/main/java/net/ornithemc/osl/entities/impl/mixin/common/SpawnEggDataAccessOld.java
@@ -0,0 +1,16 @@
+package net.ornithemc.osl.entities.impl.mixin.common;
+
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Mutable;
+import org.spongepowered.asm.mixin.gen.Accessor;
+
+import net.minecraft.entity.Entities.SpawnEggData;
+
+@Mixin(SpawnEggData.class)
+public interface SpawnEggDataAccessOld {
+
+	@Mutable
+	@Accessor("id")
+	void setId(int id);
+
+}
diff --git a/libraries/entities/entities-mc1.8.2-pre5-mc1.10.2/src/main/resources/fabric.mod.json b/libraries/entities/entities-mc1.8.2-pre5-mc1.10.2/src/main/resources/fabric.mod.json
new file mode 100644
index 00000000..ba66966f
--- /dev/null
+++ b/libraries/entities/entities-mc1.8.2-pre5-mc1.10.2/src/main/resources/fabric.mod.json
@@ -0,0 +1,38 @@
+{
+  "schemaVersion": 1,
+  "id": "osl-entities",
+  "version": "0.1.0+mc1.8.2-pre5-mc1.10.2",
+  "environment": "*",
+  "entrypoints": {
+    "init": [
+      "net.ornithemc.osl.entities.impl.EntityTypeRegistryImpl::init"
+    ]
+  },
+  "mixins": [
+    "osl.entities.mixins.json"
+  ],
+  "accessWidener": "osl.entities.classtweaker",
+  "depends": {
+    "fabricloader": "\u003e\u003d0.18.0",
+    "minecraft": "\u003e\u003d1.8.2-rc.5 \u003c\u003d1.10.2",
+    "osl-core": "\u003e\u003d0.9.0",
+    "osl-entrypoints": "\u003e\u003d0.5.0",
+    "osl-lifecycle-events": "\u003e\u003d0.6.0",
+    "osl-executors": "\u003e\u003d0.1.0",
+    "osl-text-components": "\u003e\u003d0.1.0-",
+    "osl-networking": "\u003e\u003d0.10.0",
+    "osl-networking-impl": "\u003e\u003d0.2.0",
+    "osl-registries": "\u003e\u003d0.1.0"
+  },
+  "name": "OSL Entities",
+  "description": "Entities API and events.",
+  "authors": [
+    "OrnitheMC"
+  ],
+  "contact": {
+    "homepage": "https://ornithemc.net/",
+    "issues": "https://github.com/OrnitheMC/ornithe-standard-libraries/issues",
+    "sources": "https://github.com/OrnitheMC/ornithe-standard-libraries"
+  },
+  "license": "Apache-2.0"
+}
\ No newline at end of file
diff --git a/libraries/entities/entities-mc1.8.2-pre5-mc1.10.2/src/main/resources/osl.entities.classtweaker b/libraries/entities/entities-mc1.8.2-pre5-mc1.10.2/src/main/resources/osl.entities.classtweaker
new file mode 100644
index 00000000..c8fa22c6
--- /dev/null
+++ b/libraries/entities/entities-mc1.8.2-pre5-mc1.10.2/src/main/resources/osl.entities.classtweaker
@@ -0,0 +1,9 @@
+classTweaker	v1	named
+
+accessible	field	net/minecraft/entity/Entities	KEY_TO_TYPE	Ljava/util/Map;
+accessible	field	net/minecraft/entity/Entities	TYPE_TO_KEY	Ljava/util/Map;
+accessible	field	net/minecraft/entity/Entities	ID_TO_TYPE	Ljava/util/Map;
+accessible	field	net/minecraft/entity/Entities	TYPE_TO_ID	Ljava/util/Map;
+accessible	field	net/minecraft/entity/Entities	KEY_TO_ID	Ljava/util/Map;
+accessible	field	net/minecraft/entity/Entities	SPAWN_EGG_DATA	Ljava/util/Map;
+
diff --git a/libraries/entities/entities-mc1.8.2-pre5-mc1.10.2/src/main/resources/osl.entities.mixins.json b/libraries/entities/entities-mc1.8.2-pre5-mc1.10.2/src/main/resources/osl.entities.mixins.json
new file mode 100644
index 00000000..da81152e
--- /dev/null
+++ b/libraries/entities/entities-mc1.8.2-pre5-mc1.10.2/src/main/resources/osl.entities.mixins.json
@@ -0,0 +1,21 @@
+{
+	"required": true,
+	"minVersion": "0.8",
+	"package": "net.ornithemc.osl.entities.impl.mixin",
+	"compatibilityLevel": "JAVA_8",
+	"plugin": "net.ornithemc.osl.entities.impl.EntitiesMixinPlugin",
+	"mixins": [
+		"common.EntitiesMixin",
+		"common.EntitiesMixin_15w32c",
+		"common.EntitiesMixin_15w33a",
+		"common.SpawnEggDataAccessNew",
+		"common.SpawnEggDataAccessOld"
+	],
+	"client": [
+	],
+	"server": [
+	],
+	"injectors": {
+		"defaultRequire": 1
+	}
+}
diff --git a/libraries/entities/entities-mc12w01a-mc1.8.2-pre4/build.gradle b/libraries/entities/entities-mc12w01a-mc1.8.2-pre4/build.gradle
new file mode 100644
index 00000000..0a350fdb
--- /dev/null
+++ b/libraries/entities/entities-mc12w01a-mc1.8.2-pre4/build.gradle
@@ -0,0 +1 @@
+setUpModule(project)
diff --git a/libraries/entities/entities-mc12w01a-mc1.8.2-pre4/gradle.properties b/libraries/entities/entities-mc12w01a-mc1.8.2-pre4/gradle.properties
new file mode 100644
index 00000000..6e8b2630
--- /dev/null
+++ b/libraries/entities/entities-mc12w01a-mc1.8.2-pre4/gradle.properties
@@ -0,0 +1,7 @@
+min_mc_version = 12w01a
+max_mc_version = 1.8.2-pre4
+
+minecraft_version = 1.7.2
+raven_build = 1
+sparrow_build = 1
+nests_build = 3
diff --git a/libraries/entities/entities-mc12w01a-mc1.8.2-pre4/src/main/java/net/ornithemc/osl/entities/api/EntityEvents.java b/libraries/entities/entities-mc12w01a-mc1.8.2-pre4/src/main/java/net/ornithemc/osl/entities/api/EntityEvents.java
new file mode 100644
index 00000000..d7c80c74
--- /dev/null
+++ b/libraries/entities/entities-mc12w01a-mc1.8.2-pre4/src/main/java/net/ornithemc/osl/entities/api/EntityEvents.java
@@ -0,0 +1,34 @@
+package net.ornithemc.osl.entities.api;
+
+import net.ornithemc.osl.core.api.events.Event;
+
+/**
+ * Events related to the entities lifecycle.
+ */
+public final class EntityEvents {
+
+	/**
+	 * This event is invoked upon game start-up, after Vanilla entity registration is finished.
+	 * 
+	 * <p>
+	 * Custom entity type registration should be done in a listener of this event.
+	 * Helper methods for registering entity types can be found in the {@linkplain
+	 * EntityTypeRegistry} class.
+	 * 
+	 * <p>
+	 * Listeners to this event should be registered in your mod's entrypoint,
+	 * and can be done as follows:
+	 * 
+	 * <pre>
+	 * {@code
+	 * EntityEvents.REGISTER_ENTITY_TYPES.register(() -> {
+	 * 	EntityTypeRegistry.register(NamespacedIdentifiers.from("example", "cookie_monster"), CookieMonsterEntity.class);
+	 * });
+	 * }
+	 * </pre>
+	 * 
+	 * @see EntityTypeRegistry
+	 */
+	public static final Event<Runnable> REGISTER_ENTITY_TYPES = Event.runnable();
+
+}
diff --git a/libraries/entities/entities-mc12w01a-mc1.8.2-pre4/src/main/java/net/ornithemc/osl/entities/api/EntityTypeRegistry.java b/libraries/entities/entities-mc12w01a-mc1.8.2-pre4/src/main/java/net/ornithemc/osl/entities/api/EntityTypeRegistry.java
new file mode 100644
index 00000000..7bc698fb
--- /dev/null
+++ b/libraries/entities/entities-mc12w01a-mc1.8.2-pre4/src/main/java/net/ornithemc/osl/entities/api/EntityTypeRegistry.java
@@ -0,0 +1,148 @@
+package net.ornithemc.osl.entities.api;
+
+import java.util.Set;
+
+import net.minecraft.entity.Entity;
+
+import net.ornithemc.osl.core.api.util.NamespacedIdentifier;
+import net.ornithemc.osl.entities.impl.EntityTypeRegistryImpl;
+import net.ornithemc.osl.registries.api.registry.Registry;
+import net.ornithemc.osl.registries.api.registry.ResourceKey;
+
+/**
+ * Public access to the Entity Types registry.
+ */
+public final class EntityTypeRegistry {
+
+	public static final Registry<Class<? extends Entity>> REGISTRY = EntityTypeRegistryImpl.REGISTRY;
+
+	/**
+	 * @return the numerical ID assigned to the given entity type.
+	 */
+	public static int getId(Class<? extends Entity> type) {
+		return EntityTypeRegistryImpl.getId(type);
+	}
+
+	/**
+	 * @return the namespaced ID assigned to the given entity type.
+	 */
+	public static NamespacedIdentifier getIdentifier(Class<? extends Entity> type) {
+		return EntityTypeRegistryImpl.getIdentifier(type);
+	}
+
+	/**
+	 * @return the resource key assigned to the given entity type.
+	 */
+	public static ResourceKey<Class<? extends Entity>> getKey(Class<? extends Entity> type) {
+		return EntityTypeRegistryImpl.getKey(type);
+	}
+
+	/**
+	 * @return the legacy {@code String} key assigned to the given entity type.
+	 */
+	public static String getLegacyKey(Class<? extends Entity> type) {
+		return EntityTypeRegistryImpl.getLegacyKey(type);
+	}
+
+	/**
+	 * @return the entity type mapped to the given numerical ID.
+	 */
+	public static Class<? extends Entity> getEntityType(int id) {
+		return EntityTypeRegistryImpl.getEntityType(id);
+	}
+
+	/**
+	 * @return the entity type mapped to the given namespaced ID.
+	 */
+	public static Class<? extends Entity> getEntityType(NamespacedIdentifier identifier) {
+		return EntityTypeRegistryImpl.getEntityType(identifier);
+	}
+
+	/**
+	 * @return the entity type mapped to the given resource key.
+	 */
+	public static Class<? extends Entity> getEntityType(ResourceKey<Class<? extends Entity>> key) {
+		return EntityTypeRegistryImpl.getEntityType(key);
+	}
+
+	/**
+	 * @return the entity type mapped to the given legacy {@code String} key.
+	 */
+	public static Class<? extends Entity> getEntityType(String legacyKey) {
+		return EntityTypeRegistryImpl.getEntityType(legacyKey);
+	}
+
+	/**
+	 * @return a set containing all namespaced IDs in the registry.
+	 */
+	public static Set<NamespacedIdentifier> identifierSet() {
+		return EntityTypeRegistryImpl.identifierSet();
+	}
+
+	/**
+	 * @return a set containing all resource keys in the registry.
+	 */
+	public static Set<ResourceKey<Class<? extends Entity>>> keySet() {
+		return EntityTypeRegistryImpl.keySet();
+	}
+
+	/**
+	 * @return a set containing all legacy {@code String} keys in the registry.
+	 */
+	public static Set<String> legacyKeySet() {
+		return EntityTypeRegistryImpl.legacyKeySet();
+	}
+
+	/**
+	 * @param <T>        the entity type.
+	 * @param identifier the namespaced ID of the entity type.
+	 * @param type       the entity type to register.
+	 * @return the registered entity type.
+	 */
+	public static <T extends Entity> Class<T> register(NamespacedIdentifier identifier, Class<T> type) {
+		return EntityTypeRegistryImpl.register(identifier, type);
+	}
+
+	/**
+	 * @param <T>   the entity type.
+	 * @param key   the resource key of the entity type.
+	 * @param type  the entity type to register.
+	 * @return the registered entity type.
+	 */
+	public static <T extends Entity> Class<T> register(ResourceKey<Class<? extends Entity>> key, Class<T> type) {
+		return EntityTypeRegistryImpl.register(key, type);
+	}
+
+	/**
+	 * Registers spawn egg data for the specified entity type.
+	 * 
+	 * @param identifier the identifier of entity type for which to register the spawn egg data
+	 * @param baseColor  the base color of the spawn egg.
+	 * @param spotsColor the color of the spots on the spawn egg.
+	 */
+	public static void registerSpawnEggData(NamespacedIdentifier identifier, int baseColor, int spotsColor) {
+		EntityTypeRegistryImpl.registerSpawnEggData(identifier, baseColor, spotsColor);
+	}
+
+	/**
+	 * Registers spawn egg data for the specified entity type.
+	 * 
+	 * @param key        the resource key of entity type for which to register the spawn egg data
+	 * @param baseColor  the base color of the spawn egg.
+	 * @param spotsColor the color of the spots on the spawn egg.
+	 */
+	public static void registerSpawnEggData(ResourceKey<Class<? extends Entity>> key, int baseColor, int spotsColor) {
+		EntityTypeRegistryImpl.registerSpawnEggData(key, baseColor, spotsColor);
+	}
+
+	/**
+	 * Registers spawn egg data for the specified entity type.
+	 * 
+	 * @param type       the entity type for which to register the spawn egg data
+	 * @param baseColor  the base color of the spawn egg.
+	 * @param spotsColor the color of the spots on the spawn egg.
+	 */
+	public static void registerSpawnEggData(Class<? extends Entity> type, int baseColor, int spotsColor) {
+		EntityTypeRegistryImpl.registerSpawnEggData(type, baseColor, spotsColor);
+	}
+}
diff --git a/libraries/entities/entities-mc12w01a-mc1.8.2-pre4/src/main/java/net/ornithemc/osl/entities/impl/EntitiesMixinPlugin.java b/libraries/entities/entities-mc12w01a-mc1.8.2-pre4/src/main/java/net/ornithemc/osl/entities/impl/EntitiesMixinPlugin.java
new file mode 100644
index 00000000..80df3d33
--- /dev/null
+++ b/libraries/entities/entities-mc12w01a-mc1.8.2-pre4/src/main/java/net/ornithemc/osl/entities/impl/EntitiesMixinPlugin.java
@@ -0,0 +1,52 @@
+package net.ornithemc.osl.entities.impl;
+
+import java.util.List;
+import java.util.Set;
+
+import org.objectweb.asm.tree.ClassNode;
+
+import org.spongepowered.asm.mixin.extensibility.IMixinConfigPlugin;
+import org.spongepowered.asm.mixin.extensibility.IMixinInfo;
+
+import net.ornithemc.osl.core.impl.util.MinecraftVersion;
+
+public class EntitiesMixinPlugin implements IMixinConfigPlugin {
+
+	@Override
+	public void onLoad(String mixinPackage) {
+	}
+
+	@Override
+	public String getRefMapperConfig() {
+		return null;
+	}
+
+	@Override
+	public boolean shouldApplyMixin(String targetClassName, String mixinClassName) {
+		if ("net.ornithemc.osl.entities.impl.mixin.common.EntitiesMixin_1_7_10".equals(mixinClassName)) {
+			return MinecraftVersion.resolve().compareTo("1.7.10") <= 0;
+		}
+		if ("net.ornithemc.osl.entities.impl.mixin.common.EntitiesMixin_14w02a".equals(mixinClassName)) {
+			return MinecraftVersion.resolve().compareTo("14w02a") >= 0;
+		}
+
+		return true;
+	}
+
+	@Override
+	public void acceptTargets(Set<String> myTargets, Set<String> otherTargets) {
+	}
+
+	@Override
+	public List<String> getMixins() {
+		return null;
+	}
+
+	@Override
+	public void preApply(String targetClassName, ClassNode targetClass, String mixinClassName, IMixinInfo mixinInfo) {
+	}
+
+	@Override
+	public void postApply(String targetClassName, ClassNode targetClass, String mixinClassName, IMixinInfo mixinInfo) {
+	}
+}
diff --git a/libraries/entities/entities-mc12w01a-mc1.8.2-pre4/src/main/java/net/ornithemc/osl/entities/impl/EntityTypeRegistryImpl.java b/libraries/entities/entities-mc12w01a-mc1.8.2-pre4/src/main/java/net/ornithemc/osl/entities/impl/EntityTypeRegistryImpl.java
new file mode 100644
index 00000000..b9a808c0
--- /dev/null
+++ b/libraries/entities/entities-mc12w01a-mc1.8.2-pre4/src/main/java/net/ornithemc/osl/entities/impl/EntityTypeRegistryImpl.java
@@ -0,0 +1,124 @@
+package net.ornithemc.osl.entities.impl;
+
+import java.util.Map;
+import java.util.Set;
+
+import net.minecraft.entity.Entities;
+import net.minecraft.entity.Entities.SpawnEggData;
+import net.minecraft.entity.Entity;
+
+import net.ornithemc.osl.core.api.util.NamespacedIdentifier;
+import net.ornithemc.osl.entities.api.EntityEvents;
+import net.ornithemc.osl.registries.api.registry.Registry;
+import net.ornithemc.osl.registries.api.registry.RegistryKeys;
+import net.ornithemc.osl.registries.api.registry.ResourceKey;
+import net.ornithemc.osl.registries.api.registry.SyncedRegistries;
+import net.ornithemc.osl.registries.impl.registry.RegistriesImpl;
+
+public final class EntityTypeRegistryImpl {
+
+	public static final WrappedEntityTypeRegistry REGISTRY = RegistriesImpl.register(RegistryKeys.ENTITY_TYPE, new WrappedEntityTypeRegistry(RegistryKeys.ENTITY_TYPE.identifier()), () -> Entities.KEY_TO_TYPE.getClass());
+	/*
+	 * Entities.SPAWN_EGG_DATA changes type from HashMap to Map in 14w02a so we can't reference it directly.
+	 */
+	public static Map<Integer, SpawnEggData> SPAWN_EGG_DATA;
+
+	private static boolean locked = true;
+
+	public static int getId(Class<? extends Entity> type) {
+		return REGISTRY.getId(type);
+	}
+
+	public static NamespacedIdentifier getIdentifier(Class<? extends Entity> type) {
+		return REGISTRY.getIdentifier(type);
+	}
+
+	public static ResourceKey<Class<? extends Entity>> getKey(Class<? extends Entity> type) {
+		return REGISTRY.getKey(type);
+	}
+
+	public static String getLegacyKey(Class<? extends Entity> type) {
+		return REGISTRY.getLegacyKey(type);
+	}
+
+	public static Class<? extends Entity> getEntityType(int id) {
+		return REGISTRY.get(id);
+	}
+
+	public static Class<? extends Entity> getEntityType(NamespacedIdentifier identifier) {
+		return REGISTRY.get(identifier);
+	}
+
+	public static Class<? extends Entity> getEntityType(ResourceKey<Class<? extends Entity>> key) {
+		return REGISTRY.get(key);
+	}
+
+	public static Class<? extends Entity> getEntityType(String legacyKey) {
+		return REGISTRY.get(legacyKey);
+	}
+
+	public static Set<NamespacedIdentifier> identifierSet() {
+		return REGISTRY.identifierSet();
+	}
+
+	public static Set<ResourceKey<Class<? extends Entity>>> keySet() {
+		return REGISTRY.keySet();
+	}
+
+	public static Set<String> legacyKeySet() {
+		return REGISTRY.legacyKeySet();
+	}
+
+	public static <T extends Entity> Class<T> register(NamespacedIdentifier identifier, Class<T> type) {
+		if (locked) {
+			throw new IllegalStateException("register called too early: registry locked!");
+		} else {
+			return Registry.register(REGISTRY, identifier, type);
+		}
+	}
+
+	public static <T extends Entity> Class<T> register(ResourceKey<Class<? extends Entity>> key, Class<T> type) {
+		if (locked) {
+			throw new IllegalStateException("register called too early: registry locked!");
+		} else {
+			return Registry.register(REGISTRY, key, type);
+		}
+	}
+
+	public static void registerSpawnEggData(NamespacedIdentifier identifier, int baseColor, int spotsColor) {
+		registerSpawnEggData(getEntityType(identifier), baseColor, spotsColor);
+	}
+
+	public static void registerSpawnEggData(ResourceKey<Class<? extends Entity>> key, int baseColor, int spotsColor) {
+		registerSpawnEggData(getEntityType(key), baseColor, spotsColor);
+	}
+
+	public static void registerSpawnEggData(Class<? extends Entity> type, int baseColor, int spotsColor) {
+		if (locked) {
+			throw new IllegalStateException("register called too early: registry locked!");
+		} else {
+			int id = getId(type);
+
+			if (id < 0) {
+				throw new IllegalArgumentException("Entity type " + type.getSimpleName() + " is not registered!");
+			}
+			if (!SPAWN_EGG_DATA.containsKey(id)) {
+				throw new IllegalArgumentException("Duplicate entity type ID " + id + " in spawn egg data registry!");
+			}
+
+			SPAWN_EGG_DATA.put(id, new SpawnEggData(id, baseColor, spotsColor));
+		}
+	}
+
+	public static void init() {
+		SyncedRegistries.register(RegistryKeys.ENTITY_TYPE);
+	}
+
+	public static void unlock() {
+		locked = false;
+	}
+
+	public static void registerEntityTypes() {
+		EntityEvents.REGISTER_ENTITY_TYPES.invoker().run();
+	}
+}
diff --git a/libraries/entities/entities-mc12w01a-mc1.8.2-pre4/src/main/java/net/ornithemc/osl/entities/impl/VanillaEntityTypes.java b/libraries/entities/entities-mc12w01a-mc1.8.2-pre4/src/main/java/net/ornithemc/osl/entities/impl/VanillaEntityTypes.java
new file mode 100644
index 00000000..b0a5bebc
--- /dev/null
+++ b/libraries/entities/entities-mc12w01a-mc1.8.2-pre4/src/main/java/net/ornithemc/osl/entities/impl/VanillaEntityTypes.java
@@ -0,0 +1,80 @@
+package net.ornithemc.osl.entities.impl;
+
+import com.google.common.collect.BiMap;
+import com.google.common.collect.HashBiMap;
+
+final class VanillaEntityTypes {
+
+	static final BiMap<String, String> IDENTIFIERS = HashBiMap.create();
+
+	static {
+		IDENTIFIERS.put("Item", "item");
+		IDENTIFIERS.put("XPOrb", "xp_orb");
+		IDENTIFIERS.put("AreaEffectCloud", "area_effect_cloud");
+		IDENTIFIERS.put("ThrownEgg", "egg");
+		IDENTIFIERS.put("LeashKnot", "leash_knot");
+		IDENTIFIERS.put("Painting", "painting");
+		IDENTIFIERS.put("Arrow", "arrow");
+		IDENTIFIERS.put("Snowball", "snowball");
+		IDENTIFIERS.put("Fireball", "fireball");
+		IDENTIFIERS.put("SmallFireball", "small_fireball");
+		IDENTIFIERS.put("ThrownEnderPearl", "ender_pearl");
+		IDENTIFIERS.put("EyeOfEnderSignal", "eye_of_ender_signal");
+		IDENTIFIERS.put("ThrowPotion", "potion");
+		IDENTIFIERS.put("ThrownExpBottle", "xp_bottle");
+		IDENTIFIERS.put("ItemFrame", "item_frame");
+		IDENTIFIERS.put("WitherSkull", "wither_skull");
+		IDENTIFIERS.put("PrimedTNT", "tnt");
+		IDENTIFIERS.put("FallingSand", "falling_block");
+		IDENTIFIERS.put("FireworksRocketEntity", "fireworks_rocket");
+		IDENTIFIERS.put("SpectralArrow", "spectral_arrow");
+		IDENTIFIERS.put("ShulkerBullet", "shulker_bullet");
+		IDENTIFIERS.put("DragonFireball", "dragon_fireball");
+		IDENTIFIERS.put("ArmorStand", "armor_stand");
+		IDENTIFIERS.put("Boat", "boat");
+		IDENTIFIERS.put("MinecartRideable", "minecart");
+		IDENTIFIERS.put("MinecartChest", "chest_minecart");
+		IDENTIFIERS.put("MinecartFurnace", "furnace_minecart");
+		IDENTIFIERS.put("MinecartTNT", "tnt_minecart");
+		IDENTIFIERS.put("MinecartSpawner", "spawner_minecart");
+		IDENTIFIERS.put("MinecartHopper", "hopper_minecart");
+		IDENTIFIERS.put("MinecartCommandBlock", "commandblock_minecart");
+		IDENTIFIERS.put("Mob", "mob");
+		IDENTIFIERS.put("Monster", "monster");
+		IDENTIFIERS.put("Creeper", "creeper");
+		IDENTIFIERS.put("Skeleton", "skeleton");
+		IDENTIFIERS.put("Spider", "spider");
+		IDENTIFIERS.put("Giant", "giant");
+		IDENTIFIERS.put("Zombie", "zombie");
+		IDENTIFIERS.put("Slime", "slime");
+		IDENTIFIERS.put("Ghast", "ghast");
+		IDENTIFIERS.put("PigZombie", "zombie_pigman");
+		IDENTIFIERS.put("Enderman", "enderman");
+		IDENTIFIERS.put("CaveSpider", "cave_spider");
+		IDENTIFIERS.put("Silverfish", "silverfish");
+		IDENTIFIERS.put("Blaze", "blaze");
+		IDENTIFIERS.put("LavaSlime", "magma_cube");
+		IDENTIFIERS.put("EnderDragon", "ender_dragon");
+		IDENTIFIERS.put("WitherBoss", "wither");
+		IDENTIFIERS.put("Bat", "bat");
+		IDENTIFIERS.put("Witch", "witch");
+		IDENTIFIERS.put("Endermite", "endermite");
+		IDENTIFIERS.put("Guardian", "guardian");
+		IDENTIFIERS.put("Shulker", "shulker");
+		IDENTIFIERS.put("Pig", "pig");
+		IDENTIFIERS.put("Sheep", "sheep");
+		IDENTIFIERS.put("Cow", "cow");
+		IDENTIFIERS.put("Chicken", "chicken");
+		IDENTIFIERS.put("Squid", "squid");
+		IDENTIFIERS.put("Wolf", "wolf");
+		IDENTIFIERS.put("MushroomCow", "mooshroom");
+		IDENTIFIERS.put("SnowMan", "snowman");
+		IDENTIFIERS.put("Ozelot", "ocelot");
+		IDENTIFIERS.put("VillagerGolem", "villager_golem");
+		IDENTIFIERS.put("EntityHorse", "horse");
+		IDENTIFIERS.put("Rabbit", "rabbit");
+		IDENTIFIERS.put("PolarBear", "polar_bear");
+		IDENTIFIERS.put("Villager", "villager");
+		IDENTIFIERS.put("EnderCrystal", "ender_crystal");
+	}
+}
diff --git a/libraries/entities/entities-mc12w01a-mc1.8.2-pre4/src/main/java/net/ornithemc/osl/entities/impl/WrappedEntityTypeRegistry.java b/libraries/entities/entities-mc12w01a-mc1.8.2-pre4/src/main/java/net/ornithemc/osl/entities/impl/WrappedEntityTypeRegistry.java
new file mode 100644
index 00000000..a5d44d93
--- /dev/null
+++ b/libraries/entities/entities-mc12w01a-mc1.8.2-pre4/src/main/java/net/ornithemc/osl/entities/impl/WrappedEntityTypeRegistry.java
@@ -0,0 +1,132 @@
+package net.ornithemc.osl.entities.impl;
+
+import java.util.Set;
+
+import com.google.common.collect.BiMap;
+import com.google.common.collect.HashBiMap;
+
+import net.minecraft.entity.Entities;
+import net.minecraft.entity.Entity;
+
+import net.ornithemc.osl.core.api.util.NamespacedIdentifier;
+import net.ornithemc.osl.core.api.util.NamespacedIdentifiers;
+import net.ornithemc.osl.core.impl.util.MinecraftVersion;
+import net.ornithemc.osl.registries.api.registry.ResourceKey;
+import net.ornithemc.osl.registries.api.registry.ResourceKeys;
+import net.ornithemc.osl.registries.impl.registry.SimpleRegistry;
+
+public class WrappedEntityTypeRegistry extends SimpleRegistry<Class<? extends Entity>> {
+
+	private static final boolean VANILLA_TRACKS_KEY_TO_ID = MinecraftVersion.resolve().compareTo("12w06a") >= 0;
+
+	private final BiMap<NamespacedIdentifier, String> legacyKeys = HashBiMap.create();
+
+	private boolean skipEntitiesRegister;
+
+	WrappedEntityTypeRegistry(NamespacedIdentifier identifier) {
+		super(identifier);
+	}
+
+	public void register(int id, String legacyKey, Class<? extends Entity> type) {
+		NamespacedIdentifier identifier = this.constructIdentifier(legacyKey);
+		ResourceKey<Class<? extends Entity>> key = ResourceKeys.from(this.identifier(), identifier);
+
+		this.skipEntitiesRegister = true;
+		this.register(id, key, type);
+		this.skipEntitiesRegister = false;
+	}
+
+	@Override
+	public <V extends Class<? extends Entity>> V register(int id, ResourceKey<Class<? extends Entity>> key, V type) {
+		type = super.register(id, key, type);
+
+		if (!this.skipEntitiesRegister) {
+			NamespacedIdentifier identifier = key.identifier();
+			String legacyKey = this.constructLegacyKey(identifier);
+
+			if (Entities.KEY_TO_TYPE.containsKey(legacyKey)) {
+				throw new IllegalStateException("Duplicate legacy Entity type key " + legacyKey);
+			}
+
+			Entities.KEY_TO_TYPE.put(legacyKey, type);
+			Entities.TYPE_TO_KEY.put(type, legacyKey);
+			Entities.ID_TO_TYPE.put(id, type);
+			Entities.TYPE_TO_ID.put(type, id);
+			if (VANILLA_TRACKS_KEY_TO_ID) {
+				Entities.KEY_TO_ID.put(legacyKey, id);
+			}
+		}
+
+		return type;
+	}
+
+	private String constructLegacyKey(NamespacedIdentifier identifier) {
+		return this.legacyKeys.computeIfAbsent(identifier, key -> {
+			if (identifier.namespace().equals(NamespacedIdentifiers.DEFAULT_NAMESPACE)) {
+				String legacyKey = VanillaEntityTypes.IDENTIFIERS.inverse().get(identifier.identifier());
+
+				if (legacyKey != null) {
+					return legacyKey;
+				}
+			}
+
+			return identifier.toString();
+		});
+	}
+
+	private NamespacedIdentifier constructIdentifier(String legacyKey) {
+		return this.legacyKeys.inverse().computeIfAbsent(legacyKey, key -> {
+			String identifier = VanillaEntityTypes.IDENTIFIERS.get(legacyKey);
+
+			if (identifier != null) {
+				return NamespacedIdentifiers.from(identifier);
+			}
+
+			StringBuilder sb = new StringBuilder();
+
+			// convert PascalCase to snake_case
+			for (int i = 0; i < legacyKey.length(); i++) {
+				char chr = legacyKey.charAt(i);
+
+				if (Character.isUpperCase(chr)) {
+					chr = Character.toLowerCase(chr);
+
+					if (i != 0) {
+						sb.append('_');
+					}
+				}
+
+				sb.append(chr);
+			}
+
+			return NamespacedIdentifiers.from(sb.toString());
+		});
+	}
+
+	public Class<? extends Entity> get(String legacyKey) {
+		NamespacedIdentifier identifier = this.legacyKeys.inverse().get(legacyKey);
+		return identifier == null ? null : this.get(identifier);
+	}
+
+	public String getLegacyKey(Class<? extends Entity> type) {
+		NamespacedIdentifier identifier = this.getIdentifier(type);
+		return identifier == null ? null : this.legacyKeys.get(identifier);
+	}
+
+	public Set<String> legacyKeySet() {
+		return this.legacyKeys.values();
+	}
+
+	@Override
+	public void clear() {
+		super.clear();
+
+		Entities.KEY_TO_TYPE.clear();
+		Entities.TYPE_TO_KEY.clear();
+		Entities.ID_TO_TYPE.clear();
+		Entities.TYPE_TO_ID.clear();
+		if (VANILLA_TRACKS_KEY_TO_ID) {
+			Entities.KEY_TO_ID.clear();
+		}
+	}
+}
diff --git a/libraries/entities/entities-mc12w01a-mc1.8.2-pre4/src/main/java/net/ornithemc/osl/entities/impl/entity/SpawnEggDataMapper.java b/libraries/entities/entities-mc12w01a-mc1.8.2-pre4/src/main/java/net/ornithemc/osl/entities/impl/entity/SpawnEggDataMapper.java
new file mode 100644
index 00000000..d78d9858
--- /dev/null
+++ b/libraries/entities/entities-mc12w01a-mc1.8.2-pre4/src/main/java/net/ornithemc/osl/entities/impl/entity/SpawnEggDataMapper.java
@@ -0,0 +1,68 @@
+package net.ornithemc.osl.entities.impl.entity;
+
+import java.util.Collections;
+import java.util.IdentityHashMap;
+import java.util.Map;
+import java.util.Set;
+
+import it.unimi.dsi.fastutil.ints.Int2IntFunction;
+
+import net.minecraft.entity.Entities.SpawnEggData;
+
+import net.ornithemc.osl.entities.impl.mixin.common.SpawnEggDataAccess;
+import net.ornithemc.osl.registries.api.registry.sync.IdMapper;
+import net.ornithemc.osl.registries.api.registry.sync.RegistryMappings;
+
+public class SpawnEggDataMapper implements IdMapper {
+
+	public static SpawnEggDataMapper of(Map<Integer, SpawnEggData> spawnEggData) {
+		return new SpawnEggDataMapper(spawnEggData);
+	}
+
+	private final Map<Integer, SpawnEggData> spawnEggData;
+	private final Set<SpawnEggData> missing;
+
+	private boolean applied;
+
+	private SpawnEggDataMapper(Map<Integer, SpawnEggData> spawnEggData) {
+		this.spawnEggData = spawnEggData;
+		this.missing = Collections.newSetFromMap(new IdentityHashMap<>());
+	}
+
+	@Override
+	public void apply(RegistryMappings mappings) {
+		this.missing.clear();
+		this.fixSpawnEggData(mappings::remap, true);
+
+		this.applied = true;
+	}
+
+	@Override
+	public void undo(RegistryMappings mappings) {
+		if (this.applied) {
+			this.fixSpawnEggData(mappings::unmap, false);
+			this.missing.clear();
+		}
+
+		this.applied = false;
+	}
+
+	private void fixSpawnEggData(Int2IntFunction mapper, boolean storeMissing) {
+		for (SpawnEggData spawnEgg : this.spawnEggData.values()) {
+			if (this.missing.contains(spawnEgg)) {
+				continue;
+			}
+
+			SpawnEggDataAccess spawnEggAccess = (SpawnEggDataAccess) spawnEgg;
+
+			int oldId = spawnEgg.id;
+			int newId = mapper.applyAsInt(oldId);
+
+			if (newId >= 0) {
+				spawnEggAccess.setId(newId);
+			} else if (storeMissing) {
+				this.missing.add(spawnEgg);
+			}
+		}
+	}
+}
diff --git a/libraries/entities/entities-mc12w01a-mc1.8.2-pre4/src/main/java/net/ornithemc/osl/entities/impl/mixin/common/EntitiesMixin.java b/libraries/entities/entities-mc12w01a-mc1.8.2-pre4/src/main/java/net/ornithemc/osl/entities/impl/mixin/common/EntitiesMixin.java
new file mode 100644
index 00000000..35aef159
--- /dev/null
+++ b/libraries/entities/entities-mc12w01a-mc1.8.2-pre4/src/main/java/net/ornithemc/osl/entities/impl/mixin/common/EntitiesMixin.java
@@ -0,0 +1,45 @@
+package net.ornithemc.osl.entities.impl.mixin.common;
+
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
+
+import net.minecraft.entity.Entities;
+import net.minecraft.entity.Entity;
+
+import net.ornithemc.osl.entities.impl.EntityTypeRegistryImpl;
+
+@Mixin(Entities.class)
+public class EntitiesMixin {
+
+	@Inject(
+		method = "register",
+		at = @At(
+			value = "TAIL"
+		)
+	)
+	private static void osl$entities$register(Class<? extends Entity> type, String legacyKey, int id, CallbackInfo ci) {
+		EntityTypeRegistryImpl.REGISTRY.register(id, legacyKey, type);
+	}
+
+	@Inject(
+		method = "<clinit>",
+		at = @At(
+			value = "HEAD"
+		)
+	)
+	private static void osl$entities$unlockEntityTypeRegistry(CallbackInfo ci) {
+		EntityTypeRegistryImpl.unlock();
+	}
+
+	@Inject(
+		method = "<clinit>",
+		at = @At(
+			value = "TAIL"
+		)
+	)
+	private static void osl$entities$registerEntityTypes(CallbackInfo ci) {
+		EntityTypeRegistryImpl.registerEntityTypes();
+	}
+}
diff --git a/libraries/entities/entities-mc12w01a-mc1.8.2-pre4/src/main/java/net/ornithemc/osl/entities/impl/mixin/common/EntitiesMixin_14w02a.java b/libraries/entities/entities-mc12w01a-mc1.8.2-pre4/src/main/java/net/ornithemc/osl/entities/impl/mixin/common/EntitiesMixin_14w02a.java
new file mode 100644
index 00000000..ae6d98bb
--- /dev/null
+++ b/libraries/entities/entities-mc12w01a-mc1.8.2-pre4/src/main/java/net/ornithemc/osl/entities/impl/mixin/common/EntitiesMixin_14w02a.java
@@ -0,0 +1,51 @@
+package net.ornithemc.osl.entities.impl.mixin.common;
+
+import java.util.Map;
+
+import org.objectweb.asm.Opcodes;
+
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Shadow;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.At.Shift;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
+
+import net.minecraft.entity.Entities;
+import net.minecraft.entity.Entities.SpawnEggData;
+
+import net.ornithemc.osl.core.api.util.NamespacedIdentifiers;
+import net.ornithemc.osl.entities.impl.EntityTypeRegistryImpl;
+import net.ornithemc.osl.entities.impl.entity.SpawnEggDataMapper;
+import net.ornithemc.osl.registries.api.registry.RegistryKeys;
+import net.ornithemc.osl.registries.api.registry.SyncedRegistries;
+
+@Mixin(Entities.class)
+public class EntitiesMixin_14w02a {
+
+	@Shadow
+	public static Map<Integer, SpawnEggData> f_06564953; // SPAWN_EGG_DATA
+
+	@Inject(
+		method = "<clinit>",
+		at = @At(
+			value = "FIELD",
+			target = "Lnet/minecraft/entity/Entities;f_06564953:Ljava/util/Map;",
+			opcode = Opcodes.PUTSTATIC,
+			shift = Shift.AFTER
+		)
+	)
+	private static void osl$entities$registerSpawnEggDataRegistry(CallbackInfo ci) {
+		EntityTypeRegistryImpl.SPAWN_EGG_DATA = f_06564953;
+	}
+
+	@Inject(
+		method = "<clinit>",
+		at = @At(
+			value = "TAIL"
+		)
+	)
+	private static void osl$entities$registerSpawnEggDataMapper(CallbackInfo ci) {
+		SyncedRegistries.registerMapper(RegistryKeys.ENTITY_TYPE, NamespacedIdentifiers.from("entity_type/spawn_egg_data"), SpawnEggDataMapper.of(f_06564953));
+	}
+}
diff --git a/libraries/entities/entities-mc12w01a-mc1.8.2-pre4/src/main/java/net/ornithemc/osl/entities/impl/mixin/common/EntitiesMixin_1_7_10.java b/libraries/entities/entities-mc12w01a-mc1.8.2-pre4/src/main/java/net/ornithemc/osl/entities/impl/mixin/common/EntitiesMixin_1_7_10.java
new file mode 100644
index 00000000..c0239ef8
--- /dev/null
+++ b/libraries/entities/entities-mc12w01a-mc1.8.2-pre4/src/main/java/net/ornithemc/osl/entities/impl/mixin/common/EntitiesMixin_1_7_10.java
@@ -0,0 +1,51 @@
+package net.ornithemc.osl.entities.impl.mixin.common;
+
+import java.util.HashMap;
+
+import org.objectweb.asm.Opcodes;
+
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Shadow;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.At.Shift;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
+
+import net.minecraft.entity.Entities;
+import net.minecraft.entity.Entities.SpawnEggData;
+
+import net.ornithemc.osl.core.api.util.NamespacedIdentifiers;
+import net.ornithemc.osl.entities.impl.EntityTypeRegistryImpl;
+import net.ornithemc.osl.entities.impl.entity.SpawnEggDataMapper;
+import net.ornithemc.osl.registries.api.registry.RegistryKeys;
+import net.ornithemc.osl.registries.api.registry.SyncedRegistries;
+
+@Mixin(Entities.class)
+public class EntitiesMixin_1_7_10 {
+
+	@Shadow
+	public static HashMap<Integer, SpawnEggData> SPAWN_EGG_DATA;
+
+	@Inject(
+		method = "<clinit>",
+		at = @At(
+			value = "FIELD",
+			target = "Lnet/minecraft/entity/Entities;SPAWN_EGG_DATA:Ljava/util/HashMap;",
+			opcode = Opcodes.PUTSTATIC,
+			shift = Shift.AFTER
+		)
+	)
+	private static void osl$entities$registerSpawnEggDataRegistry(CallbackInfo ci) {
+		EntityTypeRegistryImpl.SPAWN_EGG_DATA = SPAWN_EGG_DATA;
+	}
+
+	@Inject(
+		method = "<clinit>",
+		at = @At(
+			value = "TAIL"
+		)
+	)
+	private static void osl$entities$registerSpawnEggDataMapper(CallbackInfo ci) {
+		SyncedRegistries.registerMapper(RegistryKeys.ENTITY_TYPE, NamespacedIdentifiers.from("entity_type/spawn_egg_data"), SpawnEggDataMapper.of(SPAWN_EGG_DATA));
+	}
+}
diff --git a/libraries/entities/entities-mc12w01a-mc1.8.2-pre4/src/main/java/net/ornithemc/osl/entities/impl/mixin/common/SpawnEggDataAccess.java b/libraries/entities/entities-mc12w01a-mc1.8.2-pre4/src/main/java/net/ornithemc/osl/entities/impl/mixin/common/SpawnEggDataAccess.java
new file mode 100644
index 00000000..a1fa3215
--- /dev/null
+++ b/libraries/entities/entities-mc12w01a-mc1.8.2-pre4/src/main/java/net/ornithemc/osl/entities/impl/mixin/common/SpawnEggDataAccess.java
@@ -0,0 +1,16 @@
+package net.ornithemc.osl.entities.impl.mixin.common;
+
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Mutable;
+import org.spongepowered.asm.mixin.gen.Accessor;
+
+import net.minecraft.entity.Entities.SpawnEggData;
+
+@Mixin(SpawnEggData.class)
+public interface SpawnEggDataAccess {
+
+	@Mutable
+	@Accessor("id")
+	void setId(int id);
+
+}
diff --git a/libraries/entities/entities-mc12w01a-mc1.8.2-pre4/src/main/resources/fabric.mod.json b/libraries/entities/entities-mc12w01a-mc1.8.2-pre4/src/main/resources/fabric.mod.json
new file mode 100644
index 00000000..7c1b7888
--- /dev/null
+++ b/libraries/entities/entities-mc12w01a-mc1.8.2-pre4/src/main/resources/fabric.mod.json
@@ -0,0 +1,38 @@
+{
+  "schemaVersion": 1,
+  "id": "osl-entities",
+  "version": "0.1.0+mc12w01a-mc1.8.2-pre4",
+  "environment": "*",
+  "entrypoints": {
+    "init": [
+      "net.ornithemc.osl.entities.impl.EntityTypeRegistryImpl::init"
+    ]
+  },
+  "mixins": [
+    "osl.entities.mixins.json"
+  ],
+  "accessWidener": "osl.entities.classtweaker",
+  "depends": {
+    "fabricloader": "\u003e\u003d0.18.0",
+    "minecraft": "\u003e\u003d1.1-alpha.12.1.a \u003c\u003d1.8.2-rc.4",
+    "osl-core": "\u003e\u003d0.9.0",
+    "osl-entrypoints": "\u003e\u003d0.5.0",
+    "osl-lifecycle-events": "\u003e\u003d0.6.0",
+    "osl-executors": "\u003e\u003d0.1.0",
+    "osl-text-components": "\u003e\u003d0.1.0-",
+    "osl-networking": "\u003e\u003d0.10.0",
+    "osl-networking-impl": "\u003e\u003d0.2.0",
+    "osl-registries": "\u003e\u003d0.1.0"
+  },
+  "name": "OSL Entities",
+  "description": "Entities API and events.",
+  "authors": [
+    "OrnitheMC"
+  ],
+  "contact": {
+    "homepage": "https://ornithemc.net/",
+    "issues": "https://github.com/OrnitheMC/ornithe-standard-libraries/issues",
+    "sources": "https://github.com/OrnitheMC/ornithe-standard-libraries"
+  },
+  "license": "Apache-2.0"
+}
\ No newline at end of file
diff --git a/libraries/entities/entities-mc12w01a-mc1.8.2-pre4/src/main/resources/osl.entities.classtweaker b/libraries/entities/entities-mc12w01a-mc1.8.2-pre4/src/main/resources/osl.entities.classtweaker
new file mode 100644
index 00000000..b82c7fda
--- /dev/null
+++ b/libraries/entities/entities-mc12w01a-mc1.8.2-pre4/src/main/resources/osl.entities.classtweaker
@@ -0,0 +1,7 @@
+classTweaker	v1	named
+
+accessible	field	net/minecraft/entity/Entities	KEY_TO_TYPE	Ljava/util/Map;
+accessible	field	net/minecraft/entity/Entities	TYPE_TO_KEY	Ljava/util/Map;
+accessible	field	net/minecraft/entity/Entities	ID_TO_TYPE	Ljava/util/Map;
+accessible	field	net/minecraft/entity/Entities	TYPE_TO_ID	Ljava/util/Map;
+accessible	field	net/minecraft/entity/Entities	KEY_TO_ID	Ljava/util/Map;
diff --git a/libraries/entities/entities-mc12w01a-mc1.8.2-pre4/src/main/resources/osl.entities.mixins.json b/libraries/entities/entities-mc12w01a-mc1.8.2-pre4/src/main/resources/osl.entities.mixins.json
new file mode 100644
index 00000000..baf41bd9
--- /dev/null
+++ b/libraries/entities/entities-mc12w01a-mc1.8.2-pre4/src/main/resources/osl.entities.mixins.json
@@ -0,0 +1,20 @@
+{
+	"required": true,
+	"minVersion": "0.8",
+	"package": "net.ornithemc.osl.entities.impl.mixin",
+	"compatibilityLevel": "JAVA_8",
+	"plugin": "net.ornithemc.osl.entities.impl.EntitiesMixinPlugin",
+	"mixins": [
+		"common.EntitiesMixin",
+		"common.EntitiesMixin_1_7_10",
+		"common.EntitiesMixin_14w02a",
+		"common.SpawnEggDataAccess"
+	],
+	"client": [
+	],
+	"server": [
+	],
+	"injectors": {
+		"defaultRequire": 1
+	}
+}
diff --git a/libraries/entities/entities-mc16w32a-mc18w01a/build.gradle b/libraries/entities/entities-mc16w32a-mc18w01a/build.gradle
new file mode 100644
index 00000000..0a350fdb
--- /dev/null
+++ b/libraries/entities/entities-mc16w32a-mc18w01a/build.gradle
@@ -0,0 +1 @@
+setUpModule(project)
diff --git a/libraries/entities/entities-mc16w32a-mc18w01a/gradle.properties b/libraries/entities/entities-mc16w32a-mc18w01a/gradle.properties
new file mode 100644
index 00000000..6dc628d9
--- /dev/null
+++ b/libraries/entities/entities-mc16w32a-mc18w01a/gradle.properties
@@ -0,0 +1,6 @@
+min_mc_version = 16w32a
+max_mc_version = 18w01a
+
+minecraft_version = 1.12.2
+raven_build = 1
+sparrow_build = 1
diff --git a/libraries/entities/entities-mc16w32a-mc18w01a/src/main/java/net/ornithemc/osl/entities/api/EntityEvents.java b/libraries/entities/entities-mc16w32a-mc18w01a/src/main/java/net/ornithemc/osl/entities/api/EntityEvents.java
new file mode 100644
index 00000000..d7c80c74
--- /dev/null
+++ b/libraries/entities/entities-mc16w32a-mc18w01a/src/main/java/net/ornithemc/osl/entities/api/EntityEvents.java
@@ -0,0 +1,34 @@
+package net.ornithemc.osl.entities.api;
+
+import net.ornithemc.osl.core.api.events.Event;
+
+/**
+ * Events related to the entities lifecycle.
+ */
+public final class EntityEvents {
+
+	/**
+	 * This event is invoked upon game start-up, after Vanilla entity registration is finished.
+	 * 
+	 * <p>
+	 * Custom entity type registration should be done in a listener of this event.
+	 * Helper methods for registering entity types can be found in the {@linkplain
+	 * EntityTypeRegistry} class.
+	 * 
+	 * <p>
+	 * Listeners to this event should be registered in your mod's entrypoint,
+	 * and can be done as follows:
+	 * 
+	 * <pre>
+	 * {@code
+	 * EntityEvents.REGISTER_ENTITY_TYPES.register(() -> {
+	 * 	EntityTypeRegistry.register(NamespacedIdentifiers.from("example", "cookie_monster"), CookieMonsterEntity.class);
+	 * });
+	 * }
+	 * </pre>
+	 * 
+	 * @see EntityTypeRegistry
+	 */
+	public static final Event<Runnable> REGISTER_ENTITY_TYPES = Event.runnable();
+
+}
diff --git a/libraries/entities/entities-mc16w32a-mc18w01a/src/main/java/net/ornithemc/osl/entities/api/EntityTypeRegistry.java b/libraries/entities/entities-mc16w32a-mc18w01a/src/main/java/net/ornithemc/osl/entities/api/EntityTypeRegistry.java
new file mode 100644
index 00000000..be1c69ba
--- /dev/null
+++ b/libraries/entities/entities-mc16w32a-mc18w01a/src/main/java/net/ornithemc/osl/entities/api/EntityTypeRegistry.java
@@ -0,0 +1,127 @@
+package net.ornithemc.osl.entities.api;
+
+import java.util.Set;
+
+import net.minecraft.entity.Entity;
+
+import net.ornithemc.osl.core.api.util.NamespacedIdentifier;
+import net.ornithemc.osl.entities.impl.EntityTypeRegistryImpl;
+import net.ornithemc.osl.registries.api.registry.Registry;
+import net.ornithemc.osl.registries.api.registry.ResourceKey;
+
+/**
+ * Public access to the Entity Types registry.
+ */
+public final class EntityTypeRegistry {
+
+	public static final Registry<Class<? extends Entity>> REGISTRY = EntityTypeRegistryImpl.REGISTRY;
+
+	/**
+	 * @return the numerical ID assigned to the given entity type.
+	 */
+	public static int getId(Class<? extends Entity> type) {
+		return EntityTypeRegistryImpl.getId(type);
+	}
+
+	/**
+	 * @return the namespaced ID assigned to the given entity type.
+	 */
+	public static NamespacedIdentifier getIdentifier(Class<? extends Entity> type) {
+		return EntityTypeRegistryImpl.getIdentifier(type);
+	}
+
+	/**
+	 * @return the resource key assigned to the given entity type.
+	 */
+	public static ResourceKey<Class<? extends Entity>> getKey(Class<? extends Entity> type) {
+		return EntityTypeRegistryImpl.getKey(type);
+	}
+
+	/**
+	 * @return the entity type mapped to the given numerical ID.
+	 */
+	public static Class<? extends Entity> getEntityType(int id) {
+		return EntityTypeRegistryImpl.getEntityType(id);
+	}
+
+	/**
+	 * @return the entity type mapped to the given namespaced ID.
+	 */
+	public static Class<? extends Entity> getEntityType(NamespacedIdentifier identifier) {
+		return EntityTypeRegistryImpl.getEntityType(identifier);
+	}
+
+	/**
+	 * @return the entity type mapped to the given resource key.
+	 */
+	public static Class<? extends Entity> getEntityType(ResourceKey<Class<? extends Entity>> key) {
+		return EntityTypeRegistryImpl.getEntityType(key);
+	}
+
+	/**
+	 * @return a set containing all namespaced IDs in the registry.
+	 */
+	public static Set<NamespacedIdentifier> identifierSet() {
+		return EntityTypeRegistryImpl.identifierSet();
+	}
+
+	/**
+	 * @return a set containing all resource keys in the registry.
+	 */
+	public static Set<ResourceKey<Class<? extends Entity>>> keySet() {
+		return EntityTypeRegistryImpl.keySet();
+	}
+
+	/**
+	 * @param <T>        the entity type.
+	 * @param identifier the namespaced ID of the entity type.
+	 * @param type       the entity type to register.
+	 * @return the registered entity type.
+	 */
+	public static <T extends Entity> Class<T> register(NamespacedIdentifier identifier, Class<T> type) {
+		return EntityTypeRegistryImpl.register(identifier, type);
+	}
+
+	/**
+	 * @param <T>   the entity type.
+	 * @param key   the resource key of the entity type.
+	 * @param type  the entity type to register.
+	 * @return the registered entity type.
+	 */
+	public static <T extends Entity> Class<T> register(ResourceKey<Class<? extends Entity>> key, Class<T> type) {
+		return EntityTypeRegistryImpl.register(key, type);
+	}
+
+	/**
+	 * Registers spawn egg data for the specified entity type.
+	 * 
+	 * @param identifier the identifier of the entity type for which to register the spawn egg data.
+	 * @param baseColor  the base color of the spawn egg.
+	 * @param spotsColor the color of the spots on the spawn egg.
+	 */
+	public static void registerSpawnEggData(NamespacedIdentifier identifier, int baseColor, int spotsColor) {
+		EntityTypeRegistryImpl.registerSpawnEggData(identifier, baseColor, spotsColor);
+	}
+
+	/**
+	 * Registers spawn egg data for the specified entity type.
+	 * 
+	 * @param key        the resource key of the entity type for which to register the spawn egg data.
+	 * @param baseColor  the base color of the spawn egg.
+	 * @param spotsColor the color of the spots on the spawn egg.
+	 */
+	public static void registerSpawnEggData(ResourceKey<Class<? extends Entity>> key, int baseColor, int spotsColor) {
+		EntityTypeRegistryImpl.registerSpawnEggData(key, baseColor, spotsColor);
+	}
+
+	/**
+	 * Registers spawn egg data for the specified entity type.
+	 * 
+	 * @param type       the entity type for which to register the spawn egg data.
+	 * @param baseColor  the base color of the spawn egg.
+	 * @param spotsColor the color of the spots on the spawn egg.
+	 */
+	public static void registerSpawnEggData(Class<? extends Entity> type, int baseColor, int spotsColor) {
+		EntityTypeRegistryImpl.registerSpawnEggData(type, baseColor, spotsColor);
+	}
+}
diff --git a/libraries/entities/entities-mc16w32a-mc18w01a/src/main/java/net/ornithemc/osl/entities/impl/EntityTypeIdRegistry.java b/libraries/entities/entities-mc16w32a-mc18w01a/src/main/java/net/ornithemc/osl/entities/impl/EntityTypeIdRegistry.java
new file mode 100644
index 00000000..1583ed03
--- /dev/null
+++ b/libraries/entities/entities-mc16w32a-mc18w01a/src/main/java/net/ornithemc/osl/entities/impl/EntityTypeIdRegistry.java
@@ -0,0 +1,20 @@
+package net.ornithemc.osl.entities.impl;
+
+import net.minecraft.entity.Entity;
+import net.minecraft.resource.Identifier;
+import net.minecraft.util.registry.IdRegistry;
+
+/**
+ * The entity type registry is created and populated in Entities's class initializer.
+ * This breaks OSL's usual pattern of registering the registry in the API entrypoint but
+ * triggering registry population during bootstrapping, since OSL has to wrap the Vanilla
+ * registry which is not possible without triggering Entities class load and registry
+ * population.
+ * The solution: move the Vanilla registry to another class and replace the IdRegistry
+ * reference in Entities with this one.
+ */
+public final class EntityTypeIdRegistry {
+
+	public static final IdRegistry<Identifier, Class<? extends Entity>> REGISTRY = new IdRegistry<>();
+
+}
diff --git a/libraries/entities/entities-mc16w32a-mc18w01a/src/main/java/net/ornithemc/osl/entities/impl/EntityTypeRegistryImpl.java b/libraries/entities/entities-mc16w32a-mc18w01a/src/main/java/net/ornithemc/osl/entities/impl/EntityTypeRegistryImpl.java
new file mode 100644
index 00000000..4480a0a6
--- /dev/null
+++ b/libraries/entities/entities-mc16w32a-mc18w01a/src/main/java/net/ornithemc/osl/entities/impl/EntityTypeRegistryImpl.java
@@ -0,0 +1,108 @@
+package net.ornithemc.osl.entities.impl;
+
+import java.util.Set;
+
+import net.minecraft.entity.Entities;
+import net.minecraft.entity.Entities.SpawnEggData;
+import net.minecraft.entity.Entity;
+import net.minecraft.resource.Identifier;
+
+import net.ornithemc.osl.core.api.util.NamespacedIdentifier;
+import net.ornithemc.osl.entities.api.EntityEvents;
+import net.ornithemc.osl.registries.api.registry.Registry;
+import net.ornithemc.osl.registries.api.registry.RegistryKeys;
+import net.ornithemc.osl.registries.api.registry.ResourceKey;
+import net.ornithemc.osl.registries.api.registry.SyncedRegistries;
+import net.ornithemc.osl.registries.impl.registry.VanillaRegistries;
+
+public final class EntityTypeRegistryImpl {
+
+	public static final Registry<Class<? extends Entity>> REGISTRY = VanillaRegistries.registerSimple(RegistryKeys.ENTITY_TYPE, EntityTypeIdRegistry.REGISTRY, () -> Entities.REGISTRY);
+
+	private static boolean locked = true;
+
+	public static int getId(Class<? extends Entity> type) {
+		return REGISTRY.getId(type);
+	}
+
+	public static NamespacedIdentifier getIdentifier(Class<? extends Entity> type) {
+		return REGISTRY.getIdentifier(type);
+	}
+
+	public static ResourceKey<Class<? extends Entity>> getKey(Class<? extends Entity> type) {
+		return REGISTRY.getKey(type);
+	}
+
+	public static Class<? extends Entity> getEntityType(int id) {
+		return REGISTRY.get(id);
+	}
+
+	public static Class<? extends Entity> getEntityType(NamespacedIdentifier identifier) {
+		return REGISTRY.get(identifier);
+	}
+
+	public static Class<? extends Entity> getEntityType(ResourceKey<Class<? extends Entity>> key) {
+		return REGISTRY.get(key);
+	}
+
+	public static Set<NamespacedIdentifier> identifierSet() {
+		return REGISTRY.identifierSet();
+	}
+
+	public static Set<ResourceKey<Class<? extends Entity>>> keySet() {
+		return REGISTRY.keySet();
+	}
+
+	public static <T extends Entity> Class<T> register(NamespacedIdentifier identifier, Class<T> type) {
+		if (locked) {
+			throw new IllegalStateException("register called too early: registry locked!");
+		} else {
+			return Registry.register(REGISTRY, identifier, type);
+		}
+	}
+
+	public static <T extends Entity> Class<T> register(ResourceKey<Class<? extends Entity>> key, Class<T> type) {
+		if (locked) {
+			throw new IllegalStateException("register called too early: registry locked!");
+		} else {
+			return Registry.register(REGISTRY, key, type);
+		}
+	}
+
+	public static void registerSpawnEggData(NamespacedIdentifier identifier, int baseColor, int spotsColor) {
+		registerSpawnEggData(getEntityType(identifier), baseColor, spotsColor);
+	}
+
+	public static void registerSpawnEggData(ResourceKey<Class<? extends Entity>> key, int baseColor, int spotsColor) {
+		registerSpawnEggData(getEntityType(key), baseColor, spotsColor);
+	}
+
+	public static void registerSpawnEggData(Class<? extends Entity> type, int baseColor, int spotsColor) {
+		if (locked) {
+			throw new IllegalStateException("register called too early: registry locked!");
+		} else {
+			Identifier identifier = EntityTypeIdRegistry.REGISTRY.getKey(type);
+
+			if (identifier == null) {
+				throw new IllegalArgumentException("Entity type " + type.getSimpleName() + " is not registered!");
+			}
+			if (!Entities.SPAWN_EGG_DATA.containsKey(identifier)) {
+				throw new IllegalArgumentException("Duplicate entity type identifier " + identifier + " in spawn egg data registry!");
+			}
+
+			Entities.SPAWN_EGG_DATA.put(identifier, new SpawnEggData(identifier, baseColor, spotsColor));
+		}
+	}
+
+	public static void init() {
+		SyncedRegistries.register(RegistryKeys.ENTITY_TYPE);
+	}
+
+	public static void unlock() {
+		locked = false;
+	}
+
+	public static void registerEntityTypes() {
+		EntityEvents.REGISTER_ENTITY_TYPES.invoker().run();
+	}
+}
diff --git a/libraries/entities/entities-mc16w32a-mc18w01a/src/main/java/net/ornithemc/osl/entities/impl/mixin/common/EntitiesMixin.java b/libraries/entities/entities-mc16w32a-mc18w01a/src/main/java/net/ornithemc/osl/entities/impl/mixin/common/EntitiesMixin.java
new file mode 100644
index 00000000..4c4c226a
--- /dev/null
+++ b/libraries/entities/entities-mc16w32a-mc18w01a/src/main/java/net/ornithemc/osl/entities/impl/mixin/common/EntitiesMixin.java
@@ -0,0 +1,64 @@
+package net.ornithemc.osl.entities.impl.mixin.common;
+
+import java.util.List;
+
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Shadow;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.Redirect;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
+
+import net.minecraft.entity.Entities;
+import net.minecraft.entity.Entity;
+import net.minecraft.resource.Identifier;
+import net.minecraft.util.registry.IdRegistry;
+
+import net.ornithemc.osl.core.api.util.NamespacedIdentifiers;
+import net.ornithemc.osl.entities.impl.EntityTypeIdRegistry;
+import net.ornithemc.osl.entities.impl.EntityTypeRegistryImpl;
+import net.ornithemc.osl.registries.api.registry.RegistryKeys;
+import net.ornithemc.osl.registries.api.registry.SyncedRegistries;
+import net.ornithemc.osl.registries.api.registry.sync.ListMapper;
+
+@Mixin(Entities.class)
+public class EntitiesMixin {
+
+	@Shadow
+	private static List<String> NAMES;
+
+	@Redirect(
+		method = "<clinit>",
+		at = @At(
+			value = "NEW",
+			target = "net/minecraft/util/registry/IdRegistry"
+		)
+	)
+	private static IdRegistry<Identifier, Class<? extends Entity>> osl$entities$replaceIdRegistry() {
+		// this allows us to register the entity type registry in the
+		// API entrypoint without triggering an Entities class load
+		return EntityTypeIdRegistry.REGISTRY;
+	}
+
+	@Inject(
+		method = "<clinit>",
+		at = @At(
+			value = "HEAD"
+		)
+	)
+	private static void osl$entities$unlockEntityTypeRegistry(CallbackInfo ci) {
+		EntityTypeRegistryImpl.unlock();
+	}
+
+	@Inject(
+		method = "<clinit>",
+		at = @At(
+			value = "TAIL"
+		)
+	)
+	private static void osl$entities$registerEntityTypes(CallbackInfo ci) {
+		EntityTypeRegistryImpl.registerEntityTypes();
+
+		SyncedRegistries.registerMapper(RegistryKeys.ENTITY_TYPE, NamespacedIdentifiers.from("entity_type/name"), ListMapper.of(NAMES));
+	}
+}
diff --git a/libraries/entities/entities-mc16w32a-mc18w01a/src/main/resources/fabric.mod.json b/libraries/entities/entities-mc16w32a-mc18w01a/src/main/resources/fabric.mod.json
new file mode 100644
index 00000000..6bf8f2bf
--- /dev/null
+++ b/libraries/entities/entities-mc16w32a-mc18w01a/src/main/resources/fabric.mod.json
@@ -0,0 +1,37 @@
+{
+  "schemaVersion": 1,
+  "id": "osl-entities",
+  "version": "0.1.0+mc16w32a-mc18w01a",
+  "environment": "*",
+  "entrypoints": {
+    "init": [
+      "net.ornithemc.osl.entities.impl.EntityTypeRegistryImpl::init"
+    ]
+  },
+  "mixins": [
+    "osl.entities.mixins.json"
+  ],
+  "depends": {
+    "fabricloader": "\u003e\u003d0.18.0",
+    "minecraft": "\u003e\u003d1.11-alpha.16.32.a \u003c\u003d1.13-alpha.18.1.a",
+    "osl-core": "\u003e\u003d0.9.0",
+    "osl-entrypoints": "\u003e\u003d0.5.0",
+    "osl-lifecycle-events": "\u003e\u003d0.6.0",
+    "osl-executors": "\u003e\u003d0.1.0",
+    "osl-text-components": "\u003e\u003d0.1.0-",
+    "osl-networking": "\u003e\u003d0.10.0",
+    "osl-networking-impl": "\u003e\u003d0.2.0",
+    "osl-registries": "\u003e\u003d0.1.0"
+  },
+  "name": "OSL Entities",
+  "description": "Entities API and events.",
+  "authors": [
+    "OrnitheMC"
+  ],
+  "contact": {
+    "homepage": "https://ornithemc.net/",
+    "issues": "https://github.com/OrnitheMC/ornithe-standard-libraries/issues",
+    "sources": "https://github.com/OrnitheMC/ornithe-standard-libraries"
+  },
+  "license": "Apache-2.0"
+}
\ No newline at end of file
diff --git a/libraries/entities/entities-mc16w32a-mc18w01a/src/main/resources/osl.entities.mixins.json b/libraries/entities/entities-mc16w32a-mc18w01a/src/main/resources/osl.entities.mixins.json
new file mode 100644
index 00000000..06faea95
--- /dev/null
+++ b/libraries/entities/entities-mc16w32a-mc18w01a/src/main/resources/osl.entities.mixins.json
@@ -0,0 +1,16 @@
+{
+	"required": true,
+	"minVersion": "0.8",
+	"package": "net.ornithemc.osl.entities.impl.mixin",
+	"compatibilityLevel": "JAVA_8",
+	"mixins": [
+		"common.EntitiesMixin"
+	],
+	"client": [
+	],
+	"server": [
+	],
+	"injectors": {
+		"defaultRequire": 1
+	}
+}
diff --git a/libraries/entities/entities-mc18w19a-mc18w31a/build.gradle b/libraries/entities/entities-mc18w19a-mc18w31a/build.gradle
new file mode 100644
index 00000000..0a350fdb
--- /dev/null
+++ b/libraries/entities/entities-mc18w19a-mc18w31a/build.gradle
@@ -0,0 +1 @@
+setUpModule(project)
diff --git a/libraries/entities/entities-mc18w19a-mc18w31a/gradle.properties b/libraries/entities/entities-mc18w19a-mc18w31a/gradle.properties
new file mode 100644
index 00000000..a9026982
--- /dev/null
+++ b/libraries/entities/entities-mc18w19a-mc18w31a/gradle.properties
@@ -0,0 +1,4 @@
+min_mc_version = 18w19a
+max_mc_version = 18w31a
+
+minecraft_version = 1.13
diff --git a/libraries/entities/entities-mc18w19a-mc18w31a/src/main/java/net/ornithemc/osl/entities/api/EntityEvents.java b/libraries/entities/entities-mc18w19a-mc18w31a/src/main/java/net/ornithemc/osl/entities/api/EntityEvents.java
new file mode 100644
index 00000000..e5741534
--- /dev/null
+++ b/libraries/entities/entities-mc18w19a-mc18w31a/src/main/java/net/ornithemc/osl/entities/api/EntityEvents.java
@@ -0,0 +1,34 @@
+package net.ornithemc.osl.entities.api;
+
+import net.ornithemc.osl.core.api.events.Event;
+
+/**
+ * Events related to the entities lifecycle.
+ */
+public final class EntityEvents {
+
+	/**
+	 * This event is invoked upon game start-up, after Vanilla entity registration is finished.
+	 * 
+	 * <p>
+	 * Custom entity type registration should be done in a listener of this event.
+	 * Helper methods for registering entity types can be found in the {@linkplain
+	 * EntityTypeRegistry} class.
+	 * 
+	 * <p>
+	 * Listeners to this event should be registered in your mod's entrypoint,
+	 * and can be done as follows:
+	 * 
+	 * <pre>
+	 * {@code
+	 * EntityEvents.REGISTER_ENTITY_TYPES.register(() -> {
+	 * 	EntityTypeRegistry.register(NamespacedIdentifiers.from("example", "cookie_monster"), EntityTypes.builder(CookieMonsterEntity.class, CookieMonsterEntity::new));
+	 * });
+	 * }
+	 * </pre>
+	 * 
+	 * @see EntityTypeRegistry
+	 */
+	public static final Event<Runnable> REGISTER_ENTITY_TYPES = Event.runnable();
+
+}
diff --git a/libraries/entities/entities-mc18w19a-mc18w31a/src/main/java/net/ornithemc/osl/entities/api/EntityTypeRegistry.java b/libraries/entities/entities-mc18w19a-mc18w31a/src/main/java/net/ornithemc/osl/entities/api/EntityTypeRegistry.java
new file mode 100644
index 00000000..2bfaaa72
--- /dev/null
+++ b/libraries/entities/entities-mc18w19a-mc18w31a/src/main/java/net/ornithemc/osl/entities/api/EntityTypeRegistry.java
@@ -0,0 +1,95 @@
+package net.ornithemc.osl.entities.api;
+
+import java.util.Set;
+
+import net.minecraft.entity.Entity;
+import net.minecraft.entity.EntityType;
+
+import net.ornithemc.osl.core.api.util.NamespacedIdentifier;
+import net.ornithemc.osl.entities.impl.EntityTypeRegistryImpl;
+import net.ornithemc.osl.registries.api.registry.Registry;
+import net.ornithemc.osl.registries.api.registry.ResourceKey;
+
+/**
+ * Public access to the Entity Types registry.
+ */
+public final class EntityTypeRegistry {
+
+	public static final Registry<EntityType<?>> REGISTRY = EntityTypeRegistryImpl.REGISTRY;
+
+	/**
+	 * @return the numerical ID assigned to the given entity type.
+	 */
+	public static int getId(EntityType<?> type) {
+		return EntityTypeRegistryImpl.getId(type);
+	}
+
+	/**
+	 * @return the namespaced ID assigned to the given entity type.
+	 */
+	public static NamespacedIdentifier getIdentifier(EntityType<?> type) {
+		return EntityTypeRegistryImpl.getIdentifier(type);
+	}
+
+	/**
+	 * @return the resource key assigned to the given entity type.
+	 */
+	public static ResourceKey<EntityType<?>> getKey(EntityType<?> type) {
+		return EntityTypeRegistryImpl.getKey(type);
+	}
+
+	/**
+	 * @return the entity type mapped to the given numerical ID.
+	 */
+	public static EntityType<?> getEntityType(int id) {
+		return EntityTypeRegistryImpl.getEntityType(id);
+	}
+
+	/**
+	 * @return the entity type mapped to the given namespaced ID.
+	 */
+	public static EntityType<?> getEntityType(NamespacedIdentifier identifier) {
+		return EntityTypeRegistryImpl.getEntityType(identifier);
+	}
+
+	/**
+	 * @return the entity type mapped to the given resource key.
+	 */
+	public static EntityType<?> getEntityType(ResourceKey<EntityType<?>> key) {
+		return EntityTypeRegistryImpl.getEntityType(key);
+	}
+
+	/**
+	 * @return a set containing all namespaced IDs in the registry.
+	 */
+	public static Set<NamespacedIdentifier> identifierSet() {
+		return EntityTypeRegistryImpl.identifierSet();
+	}
+
+	/**
+	 * @return a set containing all resource keys in the registry.
+	 */
+	public static Set<ResourceKey<EntityType<?>>> keySet() {
+		return EntityTypeRegistryImpl.keySet();
+	}
+
+	/**
+	 * @param <T>        the entity type.
+	 * @param identifier the namespaced ID of the entity type.
+	 * @param type       the builder for the entity type to register.
+	 * @return the registered entity type.
+	 */
+	public static <T extends Entity> EntityType<T> register(NamespacedIdentifier identifier, EntityType.Builder<T> type) {
+		return EntityTypeRegistryImpl.register(identifier, type);
+	}
+
+	/**
+	 * @param <T>   the entity type.
+	 * @param key   the resource key of the entity type.
+	 * @param type  the builder for the entity type to register.
+	 * @return the registered entity type.
+	 */
+	public static <T extends Entity> EntityType<T> register(ResourceKey<EntityType<?>> key, EntityType.Builder<T> type) {
+		return EntityTypeRegistryImpl.register(key, type);
+	}
+}
diff --git a/libraries/entities/entities-mc18w19a-mc18w31a/src/main/java/net/ornithemc/osl/entities/api/EntityTypes.java b/libraries/entities/entities-mc18w19a-mc18w31a/src/main/java/net/ornithemc/osl/entities/api/EntityTypes.java
new file mode 100644
index 00000000..9610e068
--- /dev/null
+++ b/libraries/entities/entities-mc18w19a-mc18w31a/src/main/java/net/ornithemc/osl/entities/api/EntityTypes.java
@@ -0,0 +1,20 @@
+package net.ornithemc.osl.entities.api;
+
+import java.util.function.Function;
+
+import net.minecraft.entity.Entity;
+import net.minecraft.entity.EntityType;
+import net.minecraft.world.World;
+
+/**
+ * Utilities for constructing and modifying entity types.
+ */
+public final class EntityTypes {
+
+	/**
+	 * @return a new entity type builder with the given entity type class and entity factory.
+	 */
+	public static <T extends Entity> EntityType.Builder<T> builder(Class<? extends T> type, Function<? super World, ? extends T> factory) {
+		return EntityType.Builder.of(type, factory);
+	}
+}
diff --git a/libraries/entities/entities-mc18w19a-mc18w31a/src/main/java/net/ornithemc/osl/entities/impl/EntityTypeIdRegistry.java b/libraries/entities/entities-mc18w19a-mc18w31a/src/main/java/net/ornithemc/osl/entities/impl/EntityTypeIdRegistry.java
new file mode 100644
index 00000000..0d5e8984
--- /dev/null
+++ b/libraries/entities/entities-mc18w19a-mc18w31a/src/main/java/net/ornithemc/osl/entities/impl/EntityTypeIdRegistry.java
@@ -0,0 +1,20 @@
+package net.ornithemc.osl.entities.impl;
+
+import net.minecraft.entity.EntityType;
+import net.minecraft.resource.Identifier;
+import net.minecraft.util.registry.IdRegistry;
+
+/**
+ * The entity type registry is created and populated in EntityType's class initializer.
+ * This breaks OSL's usual pattern of registering the registry in the API entrypoint but
+ * triggering registry population during bootstrapping, since OSL has to wrap the Vanilla
+ * registry which is not possible without triggering EntityType class load and registry
+ * population.
+ * The solution: move the Vanilla registry to another class and replace the IdRegistry
+ * reference in EntityType with this one.
+ */
+public final class EntityTypeIdRegistry {
+
+	public static final IdRegistry<Identifier, EntityType<?>> REGISTRY = new IdRegistry<>();
+
+}
diff --git a/libraries/entities/entities-mc18w19a-mc18w31a/src/main/java/net/ornithemc/osl/entities/impl/EntityTypeRegistryImpl.java b/libraries/entities/entities-mc18w19a-mc18w31a/src/main/java/net/ornithemc/osl/entities/impl/EntityTypeRegistryImpl.java
new file mode 100644
index 00000000..aee89541
--- /dev/null
+++ b/libraries/entities/entities-mc18w19a-mc18w31a/src/main/java/net/ornithemc/osl/entities/impl/EntityTypeRegistryImpl.java
@@ -0,0 +1,81 @@
+package net.ornithemc.osl.entities.impl;
+
+import java.util.Set;
+
+import net.minecraft.entity.Entity;
+import net.minecraft.entity.EntityType;
+
+import net.ornithemc.osl.core.api.util.NamespacedIdentifier;
+import net.ornithemc.osl.entities.api.EntityEvents;
+import net.ornithemc.osl.registries.api.registry.Registry;
+import net.ornithemc.osl.registries.api.registry.RegistryKeys;
+import net.ornithemc.osl.registries.api.registry.ResourceKey;
+import net.ornithemc.osl.registries.api.registry.SyncedRegistries;
+import net.ornithemc.osl.registries.impl.registry.VanillaRegistries;
+
+public final class EntityTypeRegistryImpl {
+
+	public static final Registry<EntityType<?>> REGISTRY = VanillaRegistries.registerSimple(RegistryKeys.ENTITY_TYPE, EntityTypeIdRegistry.REGISTRY, () -> EntityType.REGISTRY);
+
+	private static boolean locked = true;
+
+	public static int getId(EntityType<?> type) {
+		return REGISTRY.getId(type);
+	}
+
+	public static NamespacedIdentifier getIdentifier(EntityType<?> type) {
+		return REGISTRY.getIdentifier(type);
+	}
+
+	public static ResourceKey<EntityType<?>> getKey(EntityType<?> type) {
+		return REGISTRY.getKey(type);
+	}
+
+	public static EntityType<?> getEntityType(int id) {
+		return REGISTRY.get(id);
+	}
+
+	public static EntityType<?> getEntityType(NamespacedIdentifier identifier) {
+		return REGISTRY.get(identifier);
+	}
+
+	public static EntityType<?> getEntityType(ResourceKey<EntityType<?>> key) {
+		return REGISTRY.get(key);
+	}
+
+	public static Set<NamespacedIdentifier> identifierSet() {
+		return REGISTRY.identifierSet();
+	}
+
+	public static Set<ResourceKey<EntityType<?>>> keySet() {
+		return REGISTRY.keySet();
+	}
+
+	public static <T extends Entity> EntityType<T> register(NamespacedIdentifier identifier, EntityType.Builder<T> type) {
+		if (locked) {
+			throw new IllegalStateException("register called too early: registry locked!");
+		} else {
+			return Registry.register(REGISTRY, identifier, type.build(null));
+		}
+	}
+
+	public static <T extends Entity> EntityType<T> register(ResourceKey<EntityType<?>> key, EntityType.Builder<T> type) {
+		if (locked) {
+			throw new IllegalStateException("register called too early: registry locked!");
+		} else {
+			return Registry.register(REGISTRY, key, type.build(null));
+		}
+	}
+
+	public static void init() {
+		SyncedRegistries.register(RegistryKeys.ENTITY_TYPE);
+	}
+
+	public static void unlock() {
+		locked = false;
+	}
+
+	public static void registerEntityTypes() {
+		EntityEvents.REGISTER_ENTITY_TYPES.invoker().run();
+	}
+}
diff --git a/libraries/entities/entities-mc18w19a-mc18w31a/src/main/java/net/ornithemc/osl/entities/impl/mixin/common/EntityTypeMixin.java b/libraries/entities/entities-mc18w19a-mc18w31a/src/main/java/net/ornithemc/osl/entities/impl/mixin/common/EntityTypeMixin.java
new file mode 100644
index 00000000..2f79e367
--- /dev/null
+++ b/libraries/entities/entities-mc18w19a-mc18w31a/src/main/java/net/ornithemc/osl/entities/impl/mixin/common/EntityTypeMixin.java
@@ -0,0 +1,51 @@
+package net.ornithemc.osl.entities.impl.mixin.common;
+
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.Redirect;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
+
+import net.minecraft.entity.EntityType;
+import net.minecraft.resource.Identifier;
+import net.minecraft.util.registry.IdRegistry;
+
+import net.ornithemc.osl.entities.impl.EntityTypeIdRegistry;
+import net.ornithemc.osl.entities.impl.EntityTypeRegistryImpl;
+
+@Mixin(EntityType.class)
+public class EntityTypeMixin {
+
+	@Redirect(
+		method = "<clinit>",
+		at = @At(
+			value = "NEW",
+			target = "net/minecraft/util/registry/IdRegistry"
+		)
+	)
+	private static IdRegistry<Identifier, EntityType<?>> osl$entities$replaceIdRegistry() {
+		// this allows us to register the entity type registry in the
+		// API entrypoint without triggering an EntityType class load
+		return EntityTypeIdRegistry.REGISTRY;
+	}
+
+	@Inject(
+		method = "<clinit>",
+		at = @At(
+			value = "HEAD"
+		)
+	)
+	private static void osl$entities$unlockEntityTypeRegistry(CallbackInfo ci) {
+		EntityTypeRegistryImpl.unlock();
+	}
+
+	@Inject(
+		method = "<clinit>",
+		at = @At(
+			value = "TAIL"
+		)
+	)
+	private static void osl$entities$registerEntityTypes(CallbackInfo ci) {
+		EntityTypeRegistryImpl.registerEntityTypes();
+	}
+}
diff --git a/libraries/entities/entities-mc18w19a-mc18w31a/src/main/resources/fabric.mod.json b/libraries/entities/entities-mc18w19a-mc18w31a/src/main/resources/fabric.mod.json
new file mode 100644
index 00000000..9d55e3a0
--- /dev/null
+++ b/libraries/entities/entities-mc18w19a-mc18w31a/src/main/resources/fabric.mod.json
@@ -0,0 +1,37 @@
+{
+  "schemaVersion": 1,
+  "id": "osl-entities",
+  "version": "0.1.0+mc18w19a-mc18w31a",
+  "environment": "*",
+  "entrypoints": {
+    "init": [
+      "net.ornithemc.osl.entities.impl.EntityTypeRegistryImpl::init"
+    ]
+  },
+  "mixins": [
+    "osl.entities.mixins.json"
+  ],
+  "depends": {
+    "fabricloader": "\u003e\u003d0.18.0",
+    "minecraft": "\u003e\u003d1.13-alpha.18.19.a \u003c\u003d1.13.1-alpha.18.31.a",
+    "osl-core": "\u003e\u003d0.9.0",
+    "osl-entrypoints": "\u003e\u003d0.5.0",
+    "osl-lifecycle-events": "\u003e\u003d0.6.0",
+    "osl-executors": "\u003e\u003d0.1.0",
+    "osl-text-components": "\u003e\u003d0.1.0-",
+    "osl-networking": "\u003e\u003d0.10.0",
+    "osl-networking-impl": "\u003e\u003d0.2.0",
+    "osl-registries": "\u003e\u003d0.1.0"
+  },
+  "name": "OSL Entities",
+  "description": "Entities API and events.",
+  "authors": [
+    "OrnitheMC"
+  ],
+  "contact": {
+    "homepage": "https://ornithemc.net/",
+    "issues": "https://github.com/OrnitheMC/ornithe-standard-libraries/issues",
+    "sources": "https://github.com/OrnitheMC/ornithe-standard-libraries"
+  },
+  "license": "Apache-2.0"
+}
\ No newline at end of file
diff --git a/libraries/entities/entities-mc18w19a-mc18w31a/src/main/resources/osl.entities.mixins.json b/libraries/entities/entities-mc18w19a-mc18w31a/src/main/resources/osl.entities.mixins.json
new file mode 100644
index 00000000..515a97de
--- /dev/null
+++ b/libraries/entities/entities-mc18w19a-mc18w31a/src/main/resources/osl.entities.mixins.json
@@ -0,0 +1,16 @@
+{
+	"required": true,
+	"minVersion": "0.8",
+	"package": "net.ornithemc.osl.entities.impl.mixin",
+	"compatibilityLevel": "JAVA_8",
+	"mixins": [
+		"common.EntityTypeMixin"
+	],
+	"client": [
+	],
+	"server": [
+	],
+	"injectors": {
+		"defaultRequire": 1
+	}
+}
diff --git a/libraries/entities/entities-mc18w32a-mc19w04b/build.gradle b/libraries/entities/entities-mc18w32a-mc19w04b/build.gradle
new file mode 100644
index 00000000..0a350fdb
--- /dev/null
+++ b/libraries/entities/entities-mc18w32a-mc19w04b/build.gradle
@@ -0,0 +1 @@
+setUpModule(project)
diff --git a/libraries/entities/entities-mc18w32a-mc19w04b/gradle.properties b/libraries/entities/entities-mc18w32a-mc19w04b/gradle.properties
new file mode 100644
index 00000000..1c1cbede
--- /dev/null
+++ b/libraries/entities/entities-mc18w32a-mc19w04b/gradle.properties
@@ -0,0 +1,4 @@
+min_mc_version = 18w32a
+max_mc_version = 19w04b
+
+minecraft_version = 1.13.2
diff --git a/libraries/entities/entities-mc18w32a-mc19w04b/src/main/java/net/ornithemc/osl/entities/api/EntityEvents.java b/libraries/entities/entities-mc18w32a-mc19w04b/src/main/java/net/ornithemc/osl/entities/api/EntityEvents.java
new file mode 100644
index 00000000..e5741534
--- /dev/null
+++ b/libraries/entities/entities-mc18w32a-mc19w04b/src/main/java/net/ornithemc/osl/entities/api/EntityEvents.java
@@ -0,0 +1,34 @@
+package net.ornithemc.osl.entities.api;
+
+import net.ornithemc.osl.core.api.events.Event;
+
+/**
+ * Events related to the entities lifecycle.
+ */
+public final class EntityEvents {
+
+	/**
+	 * This event is invoked upon game start-up, after Vanilla entity registration is finished.
+	 * 
+	 * <p>
+	 * Custom entity type registration should be done in a listener of this event.
+	 * Helper methods for registering entity types can be found in the {@linkplain
+	 * EntityTypeRegistry} class.
+	 * 
+	 * <p>
+	 * Listeners to this event should be registered in your mod's entrypoint,
+	 * and can be done as follows:
+	 * 
+	 * <pre>
+	 * {@code
+	 * EntityEvents.REGISTER_ENTITY_TYPES.register(() -> {
+	 * 	EntityTypeRegistry.register(NamespacedIdentifiers.from("example", "cookie_monster"), EntityTypes.builder(CookieMonsterEntity.class, CookieMonsterEntity::new));
+	 * });
+	 * }
+	 * </pre>
+	 * 
+	 * @see EntityTypeRegistry
+	 */
+	public static final Event<Runnable> REGISTER_ENTITY_TYPES = Event.runnable();
+
+}
diff --git a/libraries/entities/entities-mc18w32a-mc19w04b/src/main/java/net/ornithemc/osl/entities/api/EntityTypeRegistry.java b/libraries/entities/entities-mc18w32a-mc19w04b/src/main/java/net/ornithemc/osl/entities/api/EntityTypeRegistry.java
new file mode 100644
index 00000000..2cca2a1d
--- /dev/null
+++ b/libraries/entities/entities-mc18w32a-mc19w04b/src/main/java/net/ornithemc/osl/entities/api/EntityTypeRegistry.java
@@ -0,0 +1,95 @@
+package net.ornithemc.osl.entities.api;
+
+import java.util.Set;
+
+import net.minecraft.entity.Entity;
+import net.minecraft.entity.EntityType;
+
+import net.ornithemc.osl.core.api.util.NamespacedIdentifier;
+import net.ornithemc.osl.entities.impl.EntityTypeRegistryImpl;
+import net.ornithemc.osl.registries.api.registry.Registry;
+import net.ornithemc.osl.registries.api.registry.ResourceKey;
+
+/**
+ * Public access to the Block Entity Types registry.
+ */
+public final class EntityTypeRegistry {
+
+	public static final Registry<EntityType<?>> REGISTRY = EntityTypeRegistryImpl.REGISTRY;
+
+	/**
+	 * @return the numerical ID assigned to the given entity type.
+	 */
+	public static int getId(EntityType<?> type) {
+		return EntityTypeRegistryImpl.getId(type);
+	}
+
+	/**
+	 * @return the namespaced ID assigned to the given entity type.
+	 */
+	public static NamespacedIdentifier getIdentifier(EntityType<?> type) {
+		return EntityTypeRegistryImpl.getIdentifier(type);
+	}
+
+	/**
+	 * @return the resource key assigned to the given entity type.
+	 */
+	public static ResourceKey<EntityType<?>> getKey(EntityType<?> type) {
+		return EntityTypeRegistryImpl.getKey(type);
+	}
+
+	/**
+	 * @return the entity type mapped to the given numerical ID.
+	 */
+	public static EntityType<?> getEntityType(int id) {
+		return EntityTypeRegistryImpl.getEntityType(id);
+	}
+
+	/**
+	 * @return the entity type mapped to the given namespaced ID.
+	 */
+	public static EntityType<?> getEntityType(NamespacedIdentifier identifier) {
+		return EntityTypeRegistryImpl.getEntityType(identifier);
+	}
+
+	/**
+	 * @return the entity type mapped to the given resource key.
+	 */
+	public static EntityType<?> getEntityType(ResourceKey<EntityType<?>> key) {
+		return EntityTypeRegistryImpl.getEntityType(key);
+	}
+
+	/**
+	 * @return a set containing all namespaced IDs in the registry.
+	 */
+	public static Set<NamespacedIdentifier> identifierSet() {
+		return EntityTypeRegistryImpl.identifierSet();
+	}
+
+	/**
+	 * @return a set containing all resource keys in the registry.
+	 */
+	public static Set<ResourceKey<EntityType<?>>> keySet() {
+		return EntityTypeRegistryImpl.keySet();
+	}
+
+	/**
+	 * @param <T>        the entity type.
+	 * @param identifier the namespaced ID of the entity type.
+	 * @param type       the builder for the entity type to register.
+	 * @return the registered entity type.
+	 */
+	public static <T extends Entity> EntityType<T> register(NamespacedIdentifier identifier, EntityType.Builder<T> type) {
+		return EntityTypeRegistryImpl.register(identifier, type);
+	}
+
+	/**
+	 * @param <T>   the entity type.
+	 * @param key   the resource key of the entity type.
+	 * @param type  the builder for the entity type to register.
+	 * @return the registered entity type.
+	 */
+	public static <T extends Entity> EntityType<T> register(ResourceKey<EntityType<?>> key, EntityType.Builder<T> type) {
+		return EntityTypeRegistryImpl.register(key, type);
+	}
+}
diff --git a/libraries/entities/entities-mc18w32a-mc19w04b/src/main/java/net/ornithemc/osl/entities/api/EntityTypes.java b/libraries/entities/entities-mc18w32a-mc19w04b/src/main/java/net/ornithemc/osl/entities/api/EntityTypes.java
new file mode 100644
index 00000000..9610e068
--- /dev/null
+++ b/libraries/entities/entities-mc18w32a-mc19w04b/src/main/java/net/ornithemc/osl/entities/api/EntityTypes.java
@@ -0,0 +1,20 @@
+package net.ornithemc.osl.entities.api;
+
+import java.util.function.Function;
+
+import net.minecraft.entity.Entity;
+import net.minecraft.entity.EntityType;
+import net.minecraft.world.World;
+
+/**
+ * Utilities for constructing and modifying entity types.
+ */
+public final class EntityTypes {
+
+	/**
+	 * @return a new entity type builder with the given entity type class and entity factory.
+	 */
+	public static <T extends Entity> EntityType.Builder<T> builder(Class<? extends T> type, Function<? super World, ? extends T> factory) {
+		return EntityType.Builder.of(type, factory);
+	}
+}
diff --git a/libraries/entities/entities-mc18w32a-mc19w04b/src/main/java/net/ornithemc/osl/entities/impl/EntityTypeRegistryImpl.java b/libraries/entities/entities-mc18w32a-mc19w04b/src/main/java/net/ornithemc/osl/entities/impl/EntityTypeRegistryImpl.java
new file mode 100644
index 00000000..5d2dceae
--- /dev/null
+++ b/libraries/entities/entities-mc18w32a-mc19w04b/src/main/java/net/ornithemc/osl/entities/impl/EntityTypeRegistryImpl.java
@@ -0,0 +1,80 @@
+package net.ornithemc.osl.entities.impl;
+
+import java.util.Set;
+
+import net.minecraft.entity.Entity;
+import net.minecraft.entity.EntityType;
+import net.ornithemc.osl.core.api.util.NamespacedIdentifier;
+import net.ornithemc.osl.entities.api.EntityEvents;
+import net.ornithemc.osl.registries.api.registry.Registry;
+import net.ornithemc.osl.registries.api.registry.RegistryKeys;
+import net.ornithemc.osl.registries.api.registry.ResourceKey;
+import net.ornithemc.osl.registries.api.registry.SyncedRegistries;
+import net.ornithemc.osl.registries.impl.registry.VanillaRegistries;
+
+public final class EntityTypeRegistryImpl {
+
+	public static final Registry<EntityType<?>> REGISTRY = VanillaRegistries.registerSimple(RegistryKeys.ENTITY_TYPE, net.minecraft.util.registry.Registry.ENTITY_TYPE);
+
+	private static boolean locked = true;
+
+	public static int getId(EntityType<?> type) {
+		return REGISTRY.getId(type);
+	}
+
+	public static NamespacedIdentifier getIdentifier(EntityType<?> type) {
+		return REGISTRY.getIdentifier(type);
+	}
+
+	public static ResourceKey<EntityType<?>> getKey(EntityType<?> type) {
+		return REGISTRY.getKey(type);
+	}
+
+	public static EntityType<?> getEntityType(int id) {
+		return REGISTRY.get(id);
+	}
+
+	public static EntityType<?> getEntityType(NamespacedIdentifier identifier) {
+		return REGISTRY.get(identifier);
+	}
+
+	public static EntityType<?> getEntityType(ResourceKey<EntityType<?>> key) {
+		return REGISTRY.get(key);
+	}
+
+	public static Set<NamespacedIdentifier> identifierSet() {
+		return REGISTRY.identifierSet();
+	}
+
+	public static Set<ResourceKey<EntityType<?>>> keySet() {
+		return REGISTRY.keySet();
+	}
+
+	public static <T extends Entity> EntityType<T> register(NamespacedIdentifier identifier, EntityType.Builder<T> type) {
+		if (locked) {
+			throw new IllegalStateException("register called too early: registry locked!");
+		} else {
+			return Registry.register(REGISTRY, identifier, type.build(null));
+		}
+	}
+
+	public static <T extends Entity> EntityType<T> register(ResourceKey<EntityType<?>> key, EntityType.Builder<T> type) {
+		if (locked) {
+			throw new IllegalStateException("register called too early: registry locked!");
+		} else {
+			return Registry.register(REGISTRY, key, type.build(null));
+		}
+	}
+
+	public static void init() {
+		SyncedRegistries.register(RegistryKeys.ENTITY_TYPE);
+	}
+
+	public static void unlock() {
+		locked = false;
+	}
+
+	public static void registerEntityTypes() {
+		EntityEvents.REGISTER_ENTITY_TYPES.invoker().run();
+	}
+}
diff --git a/libraries/entities/entities-mc18w32a-mc19w04b/src/main/java/net/ornithemc/osl/entities/impl/mixin/common/EntityTypeMixin.java b/libraries/entities/entities-mc18w32a-mc19w04b/src/main/java/net/ornithemc/osl/entities/impl/mixin/common/EntityTypeMixin.java
new file mode 100644
index 00000000..cac88003
--- /dev/null
+++ b/libraries/entities/entities-mc18w32a-mc19w04b/src/main/java/net/ornithemc/osl/entities/impl/mixin/common/EntityTypeMixin.java
@@ -0,0 +1,34 @@
+package net.ornithemc.osl.entities.impl.mixin.common;
+
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
+
+import net.minecraft.entity.EntityType;
+
+import net.ornithemc.osl.entities.impl.EntityTypeRegistryImpl;
+
+@Mixin(EntityType.class)
+public class EntityTypeMixin {
+
+	@Inject(
+		method = "<clinit>",
+		at = @At(
+			value = "HEAD"
+		)
+	)
+	private static void osl$entities$unlockEntityTypeRegistry(CallbackInfo ci) {
+		EntityTypeRegistryImpl.unlock();
+	}
+
+	@Inject(
+		method = "<clinit>",
+		at = @At(
+			value = "TAIL"
+		)
+	)
+	private static void osl$entities$registerEntityTypes(CallbackInfo ci) {
+		EntityTypeRegistryImpl.registerEntityTypes();
+	}
+}
diff --git a/libraries/entities/entities-mc18w32a-mc19w04b/src/main/resources/fabric.mod.json b/libraries/entities/entities-mc18w32a-mc19w04b/src/main/resources/fabric.mod.json
new file mode 100644
index 00000000..11147a3d
--- /dev/null
+++ b/libraries/entities/entities-mc18w32a-mc19w04b/src/main/resources/fabric.mod.json
@@ -0,0 +1,37 @@
+{
+  "schemaVersion": 1,
+  "id": "osl-entities",
+  "version": "0.1.0+mc18w32a-mc19w04b",
+  "environment": "*",
+  "entrypoints": {
+    "init": [
+      "net.ornithemc.osl.entities.impl.EntityTypeRegistryImpl::init"
+    ]
+  },
+  "mixins": [
+    "osl.entities.mixins.json"
+  ],
+  "depends": {
+    "fabricloader": "\u003e\u003d0.18.0",
+    "minecraft": "\u003e\u003d1.13.1-alpha.18.32.a \u003c\u003d1.14-alpha.19.4.b",
+    "osl-core": "\u003e\u003d0.9.0",
+    "osl-entrypoints": "\u003e\u003d0.5.0",
+    "osl-lifecycle-events": "\u003e\u003d0.6.0",
+    "osl-executors": "\u003e\u003d0.1.0",
+    "osl-text-components": "\u003e\u003d0.1.0-",
+    "osl-networking": "\u003e\u003d0.10.0",
+    "osl-networking-impl": "\u003e\u003d0.2.0",
+    "osl-registries": "\u003e\u003d0.1.0"
+  },
+  "name": "OSL Entities",
+  "description": "Entities API and events.",
+  "authors": [
+    "OrnitheMC"
+  ],
+  "contact": {
+    "homepage": "https://ornithemc.net/",
+    "issues": "https://github.com/OrnitheMC/ornithe-standard-libraries/issues",
+    "sources": "https://github.com/OrnitheMC/ornithe-standard-libraries"
+  },
+  "license": "Apache-2.0"
+}
\ No newline at end of file
diff --git a/libraries/entities/entities-mc18w32a-mc19w04b/src/main/resources/osl.entities.mixins.json b/libraries/entities/entities-mc18w32a-mc19w04b/src/main/resources/osl.entities.mixins.json
new file mode 100644
index 00000000..515a97de
--- /dev/null
+++ b/libraries/entities/entities-mc18w32a-mc19w04b/src/main/resources/osl.entities.mixins.json
@@ -0,0 +1,16 @@
+{
+	"required": true,
+	"minVersion": "0.8",
+	"package": "net.ornithemc.osl.entities.impl.mixin",
+	"compatibilityLevel": "JAVA_8",
+	"mixins": [
+		"common.EntityTypeMixin"
+	],
+	"client": [
+	],
+	"server": [
+	],
+	"injectors": {
+		"defaultRequire": 1
+	}
+}
diff --git a/libraries/entities/entities-mc19w08a-mc1.14.4/build.gradle b/libraries/entities/entities-mc19w08a-mc1.14.4/build.gradle
new file mode 100644
index 00000000..0a350fdb
--- /dev/null
+++ b/libraries/entities/entities-mc19w08a-mc1.14.4/build.gradle
@@ -0,0 +1 @@
+setUpModule(project)
diff --git a/libraries/entities/entities-mc19w08a-mc1.14.4/gradle.properties b/libraries/entities/entities-mc19w08a-mc1.14.4/gradle.properties
new file mode 100644
index 00000000..e7132cde
--- /dev/null
+++ b/libraries/entities/entities-mc19w08a-mc1.14.4/gradle.properties
@@ -0,0 +1,4 @@
+min_mc_version = 19w08a
+max_mc_version = 1.14.4
+
+minecraft_version = 1.14.4
diff --git a/libraries/entities/entities-mc19w08a-mc1.14.4/src/main/java/net/ornithemc/osl/entities/api/EntityEvents.java b/libraries/entities/entities-mc19w08a-mc1.14.4/src/main/java/net/ornithemc/osl/entities/api/EntityEvents.java
new file mode 100644
index 00000000..bf0a5d01
--- /dev/null
+++ b/libraries/entities/entities-mc19w08a-mc1.14.4/src/main/java/net/ornithemc/osl/entities/api/EntityEvents.java
@@ -0,0 +1,34 @@
+package net.ornithemc.osl.entities.api;
+
+import net.ornithemc.osl.core.api.events.Event;
+
+/**
+ * Events related to the entities lifecycle.
+ */
+public final class EntityEvents {
+
+	/**
+	 * This event is invoked upon game start-up, after Vanilla entity registration is finished.
+	 * 
+	 * <p>
+	 * Custom entity type registration should be done in a listener of this event.
+	 * Helper methods for registering entity types can be found in the {@linkplain
+	 * EntityTypeRegistry} class.
+	 * 
+	 * <p>
+	 * Listeners to this event should be registered in your mod's entrypoint,
+	 * and can be done as follows:
+	 * 
+	 * <pre>
+	 * {@code
+	 * EntityEvents.REGISTER_ENTITY_TYPES.register(() -> {
+	 * 	EntityTypeRegistry.register(NamespacedIdentifiers.from("example", "cookie_monster"), EntityTypes.builder(CookieMonsterEntity::new, MobCategory.MISC));
+	 * });
+	 * }
+	 * </pre>
+	 * 
+	 * @see EntityTypeRegistry
+	 */
+	public static final Event<Runnable> REGISTER_ENTITY_TYPES = Event.runnable();
+
+}
diff --git a/libraries/entities/entities-mc19w08a-mc1.14.4/src/main/java/net/ornithemc/osl/entities/api/EntityTypeRegistry.java b/libraries/entities/entities-mc19w08a-mc1.14.4/src/main/java/net/ornithemc/osl/entities/api/EntityTypeRegistry.java
new file mode 100644
index 00000000..2bfaaa72
--- /dev/null
+++ b/libraries/entities/entities-mc19w08a-mc1.14.4/src/main/java/net/ornithemc/osl/entities/api/EntityTypeRegistry.java
@@ -0,0 +1,95 @@
+package net.ornithemc.osl.entities.api;
+
+import java.util.Set;
+
+import net.minecraft.entity.Entity;
+import net.minecraft.entity.EntityType;
+
+import net.ornithemc.osl.core.api.util.NamespacedIdentifier;
+import net.ornithemc.osl.entities.impl.EntityTypeRegistryImpl;
+import net.ornithemc.osl.registries.api.registry.Registry;
+import net.ornithemc.osl.registries.api.registry.ResourceKey;
+
+/**
+ * Public access to the Entity Types registry.
+ */
+public final class EntityTypeRegistry {
+
+	public static final Registry<EntityType<?>> REGISTRY = EntityTypeRegistryImpl.REGISTRY;
+
+	/**
+	 * @return the numerical ID assigned to the given entity type.
+	 */
+	public static int getId(EntityType<?> type) {
+		return EntityTypeRegistryImpl.getId(type);
+	}
+
+	/**
+	 * @return the namespaced ID assigned to the given entity type.
+	 */
+	public static NamespacedIdentifier getIdentifier(EntityType<?> type) {
+		return EntityTypeRegistryImpl.getIdentifier(type);
+	}
+
+	/**
+	 * @return the resource key assigned to the given entity type.
+	 */
+	public static ResourceKey<EntityType<?>> getKey(EntityType<?> type) {
+		return EntityTypeRegistryImpl.getKey(type);
+	}
+
+	/**
+	 * @return the entity type mapped to the given numerical ID.
+	 */
+	public static EntityType<?> getEntityType(int id) {
+		return EntityTypeRegistryImpl.getEntityType(id);
+	}
+
+	/**
+	 * @return the entity type mapped to the given namespaced ID.
+	 */
+	public static EntityType<?> getEntityType(NamespacedIdentifier identifier) {
+		return EntityTypeRegistryImpl.getEntityType(identifier);
+	}
+
+	/**
+	 * @return the entity type mapped to the given resource key.
+	 */
+	public static EntityType<?> getEntityType(ResourceKey<EntityType<?>> key) {
+		return EntityTypeRegistryImpl.getEntityType(key);
+	}
+
+	/**
+	 * @return a set containing all namespaced IDs in the registry.
+	 */
+	public static Set<NamespacedIdentifier> identifierSet() {
+		return EntityTypeRegistryImpl.identifierSet();
+	}
+
+	/**
+	 * @return a set containing all resource keys in the registry.
+	 */
+	public static Set<ResourceKey<EntityType<?>>> keySet() {
+		return EntityTypeRegistryImpl.keySet();
+	}
+
+	/**
+	 * @param <T>        the entity type.
+	 * @param identifier the namespaced ID of the entity type.
+	 * @param type       the builder for the entity type to register.
+	 * @return the registered entity type.
+	 */
+	public static <T extends Entity> EntityType<T> register(NamespacedIdentifier identifier, EntityType.Builder<T> type) {
+		return EntityTypeRegistryImpl.register(identifier, type);
+	}
+
+	/**
+	 * @param <T>   the entity type.
+	 * @param key   the resource key of the entity type.
+	 * @param type  the builder for the entity type to register.
+	 * @return the registered entity type.
+	 */
+	public static <T extends Entity> EntityType<T> register(ResourceKey<EntityType<?>> key, EntityType.Builder<T> type) {
+		return EntityTypeRegistryImpl.register(key, type);
+	}
+}
diff --git a/libraries/entities/entities-mc19w08a-mc1.14.4/src/main/java/net/ornithemc/osl/entities/api/EntityTypes.java b/libraries/entities/entities-mc19w08a-mc1.14.4/src/main/java/net/ornithemc/osl/entities/api/EntityTypes.java
new file mode 100644
index 00000000..9dab8a51
--- /dev/null
+++ b/libraries/entities/entities-mc19w08a-mc1.14.4/src/main/java/net/ornithemc/osl/entities/api/EntityTypes.java
@@ -0,0 +1,18 @@
+package net.ornithemc.osl.entities.api;
+
+import net.minecraft.entity.Entity;
+import net.minecraft.entity.EntityType;
+import net.minecraft.entity.living.mob.MobCategory;
+
+/**
+ * Utilities for constructing and modifying entity types.
+ */
+public final class EntityTypes {
+
+	/**
+	 * @return a new entity type builder with the given entity factory and mob category.
+	 */
+	public static <T extends Entity> EntityType.Builder<T> builder(EntityType.C_34376702<T> factory, MobCategory category) {
+		return EntityType.Builder.of(factory, category);
+	}
+}
diff --git a/libraries/entities/entities-mc19w08a-mc1.14.4/src/main/java/net/ornithemc/osl/entities/impl/EntityTypeRegistryImpl.java b/libraries/entities/entities-mc19w08a-mc1.14.4/src/main/java/net/ornithemc/osl/entities/impl/EntityTypeRegistryImpl.java
new file mode 100644
index 00000000..9376b9c1
--- /dev/null
+++ b/libraries/entities/entities-mc19w08a-mc1.14.4/src/main/java/net/ornithemc/osl/entities/impl/EntityTypeRegistryImpl.java
@@ -0,0 +1,81 @@
+package net.ornithemc.osl.entities.impl;
+
+import java.util.Set;
+
+import net.minecraft.entity.Entity;
+import net.minecraft.entity.EntityType;
+
+import net.ornithemc.osl.core.api.util.NamespacedIdentifier;
+import net.ornithemc.osl.entities.api.EntityEvents;
+import net.ornithemc.osl.registries.api.registry.Registry;
+import net.ornithemc.osl.registries.api.registry.RegistryKeys;
+import net.ornithemc.osl.registries.api.registry.ResourceKey;
+import net.ornithemc.osl.registries.api.registry.SyncedRegistries;
+import net.ornithemc.osl.registries.impl.registry.VanillaRegistries;
+
+public final class EntityTypeRegistryImpl {
+
+	public static final Registry<EntityType<?>> REGISTRY = VanillaRegistries.registerSimple(RegistryKeys.ENTITY_TYPE, net.minecraft.util.registry.Registry.ENTITY_TYPE);
+
+	private static boolean locked = true;
+
+	public static int getId(EntityType<?> type) {
+		return REGISTRY.getId(type);
+	}
+
+	public static NamespacedIdentifier getIdentifier(EntityType<?> type) {
+		return REGISTRY.getIdentifier(type);
+	}
+
+	public static ResourceKey<EntityType<?>> getKey(EntityType<?> type) {
+		return REGISTRY.getKey(type);
+	}
+
+	public static EntityType<?> getEntityType(int id) {
+		return REGISTRY.get(id);
+	}
+
+	public static EntityType<?> getEntityType(NamespacedIdentifier identifier) {
+		return REGISTRY.get(identifier);
+	}
+
+	public static EntityType<?> getEntityType(ResourceKey<EntityType<?>> key) {
+		return REGISTRY.get(key);
+	}
+
+	public static Set<NamespacedIdentifier> identifierSet() {
+		return REGISTRY.identifierSet();
+	}
+
+	public static Set<ResourceKey<EntityType<?>>> keySet() {
+		return REGISTRY.keySet();
+	}
+
+	public static <T extends Entity> EntityType<T> register(NamespacedIdentifier identifier, EntityType.Builder<T> type) {
+		if (locked) {
+			throw new IllegalStateException("register called too early: registry locked!");
+		} else {
+			return Registry.register(REGISTRY, identifier, type.build(null));
+		}
+	}
+
+	public static <T extends Entity> EntityType<T> register(ResourceKey<EntityType<?>> key, EntityType.Builder<T> type) {
+		if (locked) {
+			throw new IllegalStateException("register called too early: registry locked!");
+		} else {
+			return Registry.register(REGISTRY, key, type.build(null));
+		}
+	}
+
+	public static void init() {
+		SyncedRegistries.register(RegistryKeys.ENTITY_TYPE);
+	}
+
+	public static void unlock() {
+		locked = false;
+	}
+
+	public static void registerEntityTypes() {
+		EntityEvents.REGISTER_ENTITY_TYPES.invoker().run();
+	}
+}
diff --git a/libraries/entities/entities-mc19w08a-mc1.14.4/src/main/java/net/ornithemc/osl/entities/impl/mixin/common/EntityTypeMixin.java b/libraries/entities/entities-mc19w08a-mc1.14.4/src/main/java/net/ornithemc/osl/entities/impl/mixin/common/EntityTypeMixin.java
new file mode 100644
index 00000000..cac88003
--- /dev/null
+++ b/libraries/entities/entities-mc19w08a-mc1.14.4/src/main/java/net/ornithemc/osl/entities/impl/mixin/common/EntityTypeMixin.java
@@ -0,0 +1,34 @@
+package net.ornithemc.osl.entities.impl.mixin.common;
+
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
+
+import net.minecraft.entity.EntityType;
+
+import net.ornithemc.osl.entities.impl.EntityTypeRegistryImpl;
+
+@Mixin(EntityType.class)
+public class EntityTypeMixin {
+
+	@Inject(
+		method = "<clinit>",
+		at = @At(
+			value = "HEAD"
+		)
+	)
+	private static void osl$entities$unlockEntityTypeRegistry(CallbackInfo ci) {
+		EntityTypeRegistryImpl.unlock();
+	}
+
+	@Inject(
+		method = "<clinit>",
+		at = @At(
+			value = "TAIL"
+		)
+	)
+	private static void osl$entities$registerEntityTypes(CallbackInfo ci) {
+		EntityTypeRegistryImpl.registerEntityTypes();
+	}
+}
diff --git a/libraries/entities/entities-mc19w08a-mc1.14.4/src/main/resources/fabric.mod.json b/libraries/entities/entities-mc19w08a-mc1.14.4/src/main/resources/fabric.mod.json
new file mode 100644
index 00000000..fcab965f
--- /dev/null
+++ b/libraries/entities/entities-mc19w08a-mc1.14.4/src/main/resources/fabric.mod.json
@@ -0,0 +1,37 @@
+{
+  "schemaVersion": 1,
+  "id": "osl-entities",
+  "version": "0.1.0+mc19w08a-mc1.14.4",
+  "environment": "*",
+  "entrypoints": {
+    "init": [
+      "net.ornithemc.osl.entities.impl.EntityTypeRegistryImpl::init"
+    ]
+  },
+  "mixins": [
+    "osl.entities.mixins.json"
+  ],
+  "depends": {
+    "fabricloader": "\u003e\u003d0.18.0",
+    "minecraft": "\u003e\u003d1.14-alpha.19.8.a \u003c\u003d1.14.4",
+    "osl-core": "\u003e\u003d0.9.0",
+    "osl-entrypoints": "\u003e\u003d0.5.0",
+    "osl-lifecycle-events": "\u003e\u003d0.6.0",
+    "osl-executors": "\u003e\u003d0.1.0",
+    "osl-text-components": "\u003e\u003d0.1.0-",
+    "osl-networking": "\u003e\u003d0.10.0",
+    "osl-networking-impl": "\u003e\u003d0.2.0",
+    "osl-registries": "\u003e\u003d0.1.0"
+  },
+  "name": "OSL Entities",
+  "description": "Entities API and events.",
+  "authors": [
+    "OrnitheMC"
+  ],
+  "contact": {
+    "homepage": "https://ornithemc.net/",
+    "issues": "https://github.com/OrnitheMC/ornithe-standard-libraries/issues",
+    "sources": "https://github.com/OrnitheMC/ornithe-standard-libraries"
+  },
+  "license": "Apache-2.0"
+}
\ No newline at end of file
diff --git a/libraries/entities/entities-mc19w08a-mc1.14.4/src/main/resources/osl.entities.mixins.json b/libraries/entities/entities-mc19w08a-mc1.14.4/src/main/resources/osl.entities.mixins.json
new file mode 100644
index 00000000..515a97de
--- /dev/null
+++ b/libraries/entities/entities-mc19w08a-mc1.14.4/src/main/resources/osl.entities.mixins.json
@@ -0,0 +1,16 @@
+{
+	"required": true,
+	"minVersion": "0.8",
+	"package": "net.ornithemc.osl.entities.impl.mixin",
+	"compatibilityLevel": "JAVA_8",
+	"mixins": [
+		"common.EntityTypeMixin"
+	],
+	"client": [
+	],
+	"server": [
+	],
+	"injectors": {
+		"defaultRequire": 1
+	}
+}
diff --git a/libraries/entities/entities-mca1.0.1_01-mc11w48a/build.gradle b/libraries/entities/entities-mca1.0.1_01-mc11w48a/build.gradle
new file mode 100644
index 00000000..0a350fdb
--- /dev/null
+++ b/libraries/entities/entities-mca1.0.1_01-mc11w48a/build.gradle
@@ -0,0 +1 @@
+setUpModule(project)
diff --git a/libraries/entities/entities-mca1.0.1_01-mc11w48a/gradle.properties b/libraries/entities/entities-mca1.0.1_01-mc11w48a/gradle.properties
new file mode 100644
index 00000000..6caf1817
--- /dev/null
+++ b/libraries/entities/entities-mca1.0.1_01-mc11w48a/gradle.properties
@@ -0,0 +1,7 @@
+min_mc_version = a1.0.1_01
+max_mc_version = 11w48a
+
+minecraft_version = 11w48a
+client_nests_build = 11
+server_nests_build = 6
+
diff --git a/libraries/entities/entities-mca1.0.1_01-mc11w48a/src/main/java/net/ornithemc/osl/entities/api/EntityEvents.java b/libraries/entities/entities-mca1.0.1_01-mc11w48a/src/main/java/net/ornithemc/osl/entities/api/EntityEvents.java
new file mode 100644
index 00000000..d7c80c74
--- /dev/null
+++ b/libraries/entities/entities-mca1.0.1_01-mc11w48a/src/main/java/net/ornithemc/osl/entities/api/EntityEvents.java
@@ -0,0 +1,34 @@
+package net.ornithemc.osl.entities.api;
+
+import net.ornithemc.osl.core.api.events.Event;
+
+/**
+ * Events related to the entities lifecycle.
+ */
+public final class EntityEvents {
+
+	/**
+	 * This event is invoked upon game start-up, after Vanilla entity registration is finished.
+	 * 
+	 * <p>
+	 * Custom entity type registration should be done in a listener of this event.
+	 * Helper methods for registering entity types can be found in the {@linkplain
+	 * EntityTypeRegistry} class.
+	 * 
+	 * <p>
+	 * Listeners to this event should be registered in your mod's entrypoint,
+	 * and can be done as follows:
+	 * 
+	 * <pre>
+	 * {@code
+	 * EntityEvents.REGISTER_ENTITY_TYPES.register(() -> {
+	 * 	EntityTypeRegistry.register(NamespacedIdentifiers.from("example", "cookie_monster"), CookieMonsterEntity.class);
+	 * });
+	 * }
+	 * </pre>
+	 * 
+	 * @see EntityTypeRegistry
+	 */
+	public static final Event<Runnable> REGISTER_ENTITY_TYPES = Event.runnable();
+
+}
diff --git a/libraries/entities/entities-mca1.0.1_01-mc11w48a/src/main/java/net/ornithemc/osl/entities/api/EntityTypeRegistry.java b/libraries/entities/entities-mca1.0.1_01-mc11w48a/src/main/java/net/ornithemc/osl/entities/api/EntityTypeRegistry.java
new file mode 100644
index 00000000..c188c356
--- /dev/null
+++ b/libraries/entities/entities-mca1.0.1_01-mc11w48a/src/main/java/net/ornithemc/osl/entities/api/EntityTypeRegistry.java
@@ -0,0 +1,115 @@
+package net.ornithemc.osl.entities.api;
+
+import java.util.Set;
+
+import net.minecraft.entity.Entity;
+
+import net.ornithemc.osl.core.api.util.NamespacedIdentifier;
+import net.ornithemc.osl.entities.impl.EntityTypeRegistryImpl;
+import net.ornithemc.osl.registries.api.registry.Registry;
+import net.ornithemc.osl.registries.api.registry.ResourceKey;
+
+/**
+ * Public access to the Entity Types registry.
+ */
+public final class EntityTypeRegistry {
+
+	public static final Registry<Class<? extends Entity>> REGISTRY = EntityTypeRegistryImpl.REGISTRY;
+
+	/**
+	 * @return the numerical ID assigned to the given entity type.
+	 */
+	public static int getId(Class<? extends Entity> type) {
+		return EntityTypeRegistryImpl.getId(type);
+	}
+
+	/**
+	 * @return the namespaced ID assigned to the given entity type.
+	 */
+	public static NamespacedIdentifier getIdentifier(Class<? extends Entity> type) {
+		return EntityTypeRegistryImpl.getIdentifier(type);
+	}
+
+	/**
+	 * @return the resource key assigned to the given entity type.
+	 */
+	public static ResourceKey<Class<? extends Entity>> getKey(Class<? extends Entity> type) {
+		return EntityTypeRegistryImpl.getKey(type);
+	}
+
+	/**
+	 * @return the legacy {@code String} key assigned to the given entity type.
+	 */
+	public static String getLegacyKey(Class<? extends Entity> type) {
+		return EntityTypeRegistryImpl.getLegacyKey(type);
+	}
+
+	/**
+	 * @return the entity type mapped to the given numerical ID.
+	 */
+	public static Class<? extends Entity> getEntityType(int id) {
+		return EntityTypeRegistryImpl.getEntityType(id);
+	}
+
+	/**
+	 * @return the entity type mapped to the given namespaced ID.
+	 */
+	public static Class<? extends Entity> getEntityType(NamespacedIdentifier identifier) {
+		return EntityTypeRegistryImpl.getEntityType(identifier);
+	}
+
+	/**
+	 * @return the entity type mapped to the given resource key.
+	 */
+	public static Class<? extends Entity> getEntityType(ResourceKey<Class<? extends Entity>> key) {
+		return EntityTypeRegistryImpl.getEntityType(key);
+	}
+
+	/**
+	 * @return the entity type mapped to the given legacy {@code String} key.
+	 */
+	public static Class<? extends Entity> getEntityType(String legacyKey) {
+		return EntityTypeRegistryImpl.getEntityType(legacyKey);
+	}
+
+	/**
+	 * @return a set containing all namespaced IDs in the registry.
+	 */
+	public static Set<NamespacedIdentifier> identifierSet() {
+		return EntityTypeRegistryImpl.identifierSet();
+	}
+
+	/**
+	 * @return a set containing all resource keys in the registry.
+	 */
+	public static Set<ResourceKey<Class<? extends Entity>>> keySet() {
+		return EntityTypeRegistryImpl.keySet();
+	}
+
+	/**
+	 * @return a set containing all legacy {@code String} keys in the registry.
+	 */
+	public static Set<String> legacyKeySet() {
+		return EntityTypeRegistryImpl.legacyKeySet();
+	}
+
+	/**
+	 * @param <T>        the entity type.
+	 * @param identifier the namespaced ID of the entity type.
+	 * @param type       the entity type to register.
+	 * @return the registered entity type.
+	 */
+	public static <T extends Entity> Class<T> register(NamespacedIdentifier identifier, Class<T> type) {
+		return EntityTypeRegistryImpl.register(identifier, type);
+	}
+
+	/**
+	 * @param <T>   the entity type.
+	 * @param key   the resource key of the entity type.
+	 * @param type  the entity type to register.
+	 * @return the registered entity type.
+	 */
+	public static <T extends Entity> Class<T> register(ResourceKey<Class<? extends Entity>> key, Class<T> type) {
+		return EntityTypeRegistryImpl.register(key, type);
+	}
+}
diff --git a/libraries/entities/entities-mca1.0.1_01-mc11w48a/src/main/java/net/ornithemc/osl/entities/impl/EntitiesMixinPlugin.java b/libraries/entities/entities-mca1.0.1_01-mc11w48a/src/main/java/net/ornithemc/osl/entities/impl/EntitiesMixinPlugin.java
new file mode 100644
index 00000000..9ed7bb12
--- /dev/null
+++ b/libraries/entities/entities-mca1.0.1_01-mc11w48a/src/main/java/net/ornithemc/osl/entities/impl/EntitiesMixinPlugin.java
@@ -0,0 +1,59 @@
+package net.ornithemc.osl.entities.impl;
+
+import java.util.List;
+import java.util.Set;
+
+import org.objectweb.asm.tree.ClassNode;
+
+import org.spongepowered.asm.mixin.extensibility.IMixinConfigPlugin;
+import org.spongepowered.asm.mixin.extensibility.IMixinInfo;
+
+import net.fabricmc.api.EnvType;
+import net.fabricmc.loader.api.FabricLoader;
+
+import net.ornithemc.osl.core.impl.util.MinecraftVersion;
+
+public class EntitiesMixinPlugin implements IMixinConfigPlugin {
+
+	public static final boolean VANILLA_ENTITY_TYPES_HAVE_IDS = (FabricLoader.getInstance().getEnvironmentType() == EnvType.CLIENT)
+		? MinecraftVersion.resolve().compareTo("a1.0.17") >= 0
+		: MinecraftVersion.resolve().compareTo("a0.1.4") >= 0;
+
+	@Override
+	public void onLoad(String mixinPackage) {
+	}
+
+	@Override
+	public String getRefMapperConfig() {
+		return null;
+	}
+
+	@Override
+	public boolean shouldApplyMixin(String targetClassName, String mixinClassName) {
+		if ("net.ornithemc.osl.entities.impl.mixin.common.EntitiesMixinNew".equals(mixinClassName)) {
+			return VANILLA_ENTITY_TYPES_HAVE_IDS;
+		}
+		if ("net.ornithemc.osl.entities.impl.mixin.common.EntitiesMixinOld".equals(mixinClassName)) {
+			return !VANILLA_ENTITY_TYPES_HAVE_IDS;
+		}
+
+		return true;
+	}
+
+	@Override
+	public void acceptTargets(Set<String> myTargets, Set<String> otherTargets) {
+	}
+
+	@Override
+	public List<String> getMixins() {
+		return null;
+	}
+
+	@Override
+	public void preApply(String targetClassName, ClassNode targetClass, String mixinClassName, IMixinInfo mixinInfo) {
+	}
+
+	@Override
+	public void postApply(String targetClassName, ClassNode targetClass, String mixinClassName, IMixinInfo mixinInfo) {
+	}
+}
diff --git a/libraries/entities/entities-mca1.0.1_01-mc11w48a/src/main/java/net/ornithemc/osl/entities/impl/EntityTypeRegistryImpl.java b/libraries/entities/entities-mca1.0.1_01-mc11w48a/src/main/java/net/ornithemc/osl/entities/impl/EntityTypeRegistryImpl.java
new file mode 100644
index 00000000..d17e999e
--- /dev/null
+++ b/libraries/entities/entities-mca1.0.1_01-mc11w48a/src/main/java/net/ornithemc/osl/entities/impl/EntityTypeRegistryImpl.java
@@ -0,0 +1,93 @@
+package net.ornithemc.osl.entities.impl;
+
+import java.util.Set;
+
+import net.minecraft.entity.Entities;
+import net.minecraft.entity.Entity;
+
+import net.ornithemc.osl.core.api.util.NamespacedIdentifier;
+import net.ornithemc.osl.entities.api.EntityEvents;
+import net.ornithemc.osl.registries.api.registry.Registry;
+import net.ornithemc.osl.registries.api.registry.RegistryKeys;
+import net.ornithemc.osl.registries.api.registry.ResourceKey;
+import net.ornithemc.osl.registries.api.registry.SyncedRegistries;
+import net.ornithemc.osl.registries.impl.registry.RegistriesImpl;
+
+public final class EntityTypeRegistryImpl {
+
+	public static final WrappedEntityTypeRegistry REGISTRY = RegistriesImpl.register(RegistryKeys.ENTITY_TYPE, new WrappedEntityTypeRegistry(RegistryKeys.ENTITY_TYPE.identifier()), () -> Entities.KEY_TO_TYPE.getClass());
+
+	private static boolean locked = true;
+
+	public static int getId(Class<? extends Entity> type) {
+		return REGISTRY.getId(type);
+	}
+
+	public static NamespacedIdentifier getIdentifier(Class<? extends Entity> type) {
+		return REGISTRY.getIdentifier(type);
+	}
+
+	public static ResourceKey<Class<? extends Entity>> getKey(Class<? extends Entity> type) {
+		return REGISTRY.getKey(type);
+	}
+
+	public static String getLegacyKey(Class<? extends Entity> type) {
+		return REGISTRY.getLegacyKey(type);
+	}
+
+	public static Class<? extends Entity> getEntityType(int id) {
+		return REGISTRY.get(id);
+	}
+
+	public static Class<? extends Entity> getEntityType(NamespacedIdentifier identifier) {
+		return REGISTRY.get(identifier);
+	}
+
+	public static Class<? extends Entity> getEntityType(ResourceKey<Class<? extends Entity>> key) {
+		return REGISTRY.get(key);
+	}
+
+	public static Class<? extends Entity> getEntityType(String legacyKey) {
+		return REGISTRY.get(legacyKey);
+	}
+
+	public static Set<NamespacedIdentifier> identifierSet() {
+		return REGISTRY.identifierSet();
+	}
+
+	public static Set<ResourceKey<Class<? extends Entity>>> keySet() {
+		return REGISTRY.keySet();
+	}
+
+	public static Set<String> legacyKeySet() {
+		return REGISTRY.legacyKeySet();
+	}
+
+	public static <T extends Entity> Class<T> register(NamespacedIdentifier identifier, Class<T> type) {
+		if (locked) {
+			throw new IllegalStateException("register called too early: registry locked!");
+		} else {
+			return Registry.register(REGISTRY, identifier, type);
+		}
+	}
+
+	public static <T extends Entity> Class<T> register(ResourceKey<Class<? extends Entity>> key, Class<T> type) {
+		if (locked) {
+			throw new IllegalStateException("register called too early: registry locked!");
+		} else {
+			return Registry.register(REGISTRY, key, type);
+		}
+	}
+
+	public static void init() {
+		SyncedRegistries.register(RegistryKeys.ENTITY_TYPE);
+	}
+
+	public static void unlock() {
+		locked = false;
+	}
+
+	public static void registerEntityTypes() {
+		EntityEvents.REGISTER_ENTITY_TYPES.invoker().run();
+	}
+}
diff --git a/libraries/entities/entities-mca1.0.1_01-mc11w48a/src/main/java/net/ornithemc/osl/entities/impl/VanillaEntityTypes.java b/libraries/entities/entities-mca1.0.1_01-mc11w48a/src/main/java/net/ornithemc/osl/entities/impl/VanillaEntityTypes.java
new file mode 100644
index 00000000..b0a5bebc
--- /dev/null
+++ b/libraries/entities/entities-mca1.0.1_01-mc11w48a/src/main/java/net/ornithemc/osl/entities/impl/VanillaEntityTypes.java
@@ -0,0 +1,80 @@
+package net.ornithemc.osl.entities.impl;
+
+import com.google.common.collect.BiMap;
+import com.google.common.collect.HashBiMap;
+
+final class VanillaEntityTypes {
+
+	static final BiMap<String, String> IDENTIFIERS = HashBiMap.create();
+
+	static {
+		IDENTIFIERS.put("Item", "item");
+		IDENTIFIERS.put("XPOrb", "xp_orb");
+		IDENTIFIERS.put("AreaEffectCloud", "area_effect_cloud");
+		IDENTIFIERS.put("ThrownEgg", "egg");
+		IDENTIFIERS.put("LeashKnot", "leash_knot");
+		IDENTIFIERS.put("Painting", "painting");
+		IDENTIFIERS.put("Arrow", "arrow");
+		IDENTIFIERS.put("Snowball", "snowball");
+		IDENTIFIERS.put("Fireball", "fireball");
+		IDENTIFIERS.put("SmallFireball", "small_fireball");
+		IDENTIFIERS.put("ThrownEnderPearl", "ender_pearl");
+		IDENTIFIERS.put("EyeOfEnderSignal", "eye_of_ender_signal");
+		IDENTIFIERS.put("ThrowPotion", "potion");
+		IDENTIFIERS.put("ThrownExpBottle", "xp_bottle");
+		IDENTIFIERS.put("ItemFrame", "item_frame");
+		IDENTIFIERS.put("WitherSkull", "wither_skull");
+		IDENTIFIERS.put("PrimedTNT", "tnt");
+		IDENTIFIERS.put("FallingSand", "falling_block");
+		IDENTIFIERS.put("FireworksRocketEntity", "fireworks_rocket");
+		IDENTIFIERS.put("SpectralArrow", "spectral_arrow");
+		IDENTIFIERS.put("ShulkerBullet", "shulker_bullet");
+		IDENTIFIERS.put("DragonFireball", "dragon_fireball");
+		IDENTIFIERS.put("ArmorStand", "armor_stand");
+		IDENTIFIERS.put("Boat", "boat");
+		IDENTIFIERS.put("MinecartRideable", "minecart");
+		IDENTIFIERS.put("MinecartChest", "chest_minecart");
+		IDENTIFIERS.put("MinecartFurnace", "furnace_minecart");
+		IDENTIFIERS.put("MinecartTNT", "tnt_minecart");
+		IDENTIFIERS.put("MinecartSpawner", "spawner_minecart");
+		IDENTIFIERS.put("MinecartHopper", "hopper_minecart");
+		IDENTIFIERS.put("MinecartCommandBlock", "commandblock_minecart");
+		IDENTIFIERS.put("Mob", "mob");
+		IDENTIFIERS.put("Monster", "monster");
+		IDENTIFIERS.put("Creeper", "creeper");
+		IDENTIFIERS.put("Skeleton", "skeleton");
+		IDENTIFIERS.put("Spider", "spider");
+		IDENTIFIERS.put("Giant", "giant");
+		IDENTIFIERS.put("Zombie", "zombie");
+		IDENTIFIERS.put("Slime", "slime");
+		IDENTIFIERS.put("Ghast", "ghast");
+		IDENTIFIERS.put("PigZombie", "zombie_pigman");
+		IDENTIFIERS.put("Enderman", "enderman");
+		IDENTIFIERS.put("CaveSpider", "cave_spider");
+		IDENTIFIERS.put("Silverfish", "silverfish");
+		IDENTIFIERS.put("Blaze", "blaze");
+		IDENTIFIERS.put("LavaSlime", "magma_cube");
+		IDENTIFIERS.put("EnderDragon", "ender_dragon");
+		IDENTIFIERS.put("WitherBoss", "wither");
+		IDENTIFIERS.put("Bat", "bat");
+		IDENTIFIERS.put("Witch", "witch");
+		IDENTIFIERS.put("Endermite", "endermite");
+		IDENTIFIERS.put("Guardian", "guardian");
+		IDENTIFIERS.put("Shulker", "shulker");
+		IDENTIFIERS.put("Pig", "pig");
+		IDENTIFIERS.put("Sheep", "sheep");
+		IDENTIFIERS.put("Cow", "cow");
+		IDENTIFIERS.put("Chicken", "chicken");
+		IDENTIFIERS.put("Squid", "squid");
+		IDENTIFIERS.put("Wolf", "wolf");
+		IDENTIFIERS.put("MushroomCow", "mooshroom");
+		IDENTIFIERS.put("SnowMan", "snowman");
+		IDENTIFIERS.put("Ozelot", "ocelot");
+		IDENTIFIERS.put("VillagerGolem", "villager_golem");
+		IDENTIFIERS.put("EntityHorse", "horse");
+		IDENTIFIERS.put("Rabbit", "rabbit");
+		IDENTIFIERS.put("PolarBear", "polar_bear");
+		IDENTIFIERS.put("Villager", "villager");
+		IDENTIFIERS.put("EnderCrystal", "ender_crystal");
+	}
+}
diff --git a/libraries/entities/entities-mca1.0.1_01-mc11w48a/src/main/java/net/ornithemc/osl/entities/impl/WrappedEntityTypeRegistry.java b/libraries/entities/entities-mca1.0.1_01-mc11w48a/src/main/java/net/ornithemc/osl/entities/impl/WrappedEntityTypeRegistry.java
new file mode 100644
index 00000000..4c5f7faf
--- /dev/null
+++ b/libraries/entities/entities-mca1.0.1_01-mc11w48a/src/main/java/net/ornithemc/osl/entities/impl/WrappedEntityTypeRegistry.java
@@ -0,0 +1,139 @@
+package net.ornithemc.osl.entities.impl;
+
+import java.util.Set;
+
+import com.google.common.collect.BiMap;
+import com.google.common.collect.HashBiMap;
+
+import net.minecraft.entity.Entities;
+import net.minecraft.entity.Entity;
+
+import net.ornithemc.osl.core.api.util.NamespacedIdentifier;
+import net.ornithemc.osl.core.api.util.NamespacedIdentifiers;
+import net.ornithemc.osl.registries.api.registry.ResourceKey;
+import net.ornithemc.osl.registries.api.registry.ResourceKeys;
+import net.ornithemc.osl.registries.impl.registry.SimpleRegistry;
+
+public class WrappedEntityTypeRegistry extends SimpleRegistry<Class<? extends Entity>> {
+
+	private static final boolean VANILLA_TRACKS_IDS = EntitiesMixinPlugin.VANILLA_ENTITY_TYPES_HAVE_IDS;
+
+	private final BiMap<NamespacedIdentifier, String> legacyKeys = HashBiMap.create();
+
+	private boolean skipEntitiesRegister;
+
+	WrappedEntityTypeRegistry(NamespacedIdentifier identifier) {
+		super(identifier);
+	}
+
+	public void register(String legacyKey, Class<? extends Entity> type) {
+		this.register(-1, legacyKey, type);
+	}
+
+	public void register(int id, String legacyKey, Class<? extends Entity> type) {
+		NamespacedIdentifier identifier = this.constructIdentifier(legacyKey);
+		ResourceKey<Class<? extends Entity>> key = ResourceKeys.from(this.identifier(), identifier);
+
+		this.skipEntitiesRegister = true;
+
+		if (id < 0) {
+			this.register(key, type);
+		} else {
+			this.register(id, key, type);
+		}
+
+		this.skipEntitiesRegister = false;
+	}
+
+	@Override
+	public <V extends Class<? extends Entity>> V register(int id, ResourceKey<Class<? extends Entity>> key, V type) {
+		type = super.register(id, key, type);
+
+		if (!this.skipEntitiesRegister) {
+			NamespacedIdentifier identifier = key.identifier();
+			String legacyKey = this.constructLegacyKey(identifier);
+
+			if (Entities.KEY_TO_TYPE.containsKey(legacyKey)) {
+				throw new IllegalStateException("Duplicate legacy Entity type key " + legacyKey);
+			}
+
+			Entities.KEY_TO_TYPE.put(legacyKey, type);
+			Entities.TYPE_TO_KEY.put(type, legacyKey);
+			if (VANILLA_TRACKS_IDS) {
+				Entities.ID_TO_TYPE.put(id, type);
+				Entities.TYPE_TO_ID.put(type, id);
+			}
+		}
+
+		return type;
+	}
+
+	private String constructLegacyKey(NamespacedIdentifier identifier) {
+		return this.legacyKeys.computeIfAbsent(identifier, key -> {
+			if (identifier.namespace().equals(NamespacedIdentifiers.DEFAULT_NAMESPACE)) {
+				String legacyKey = VanillaEntityTypes.IDENTIFIERS.inverse().get(identifier.identifier());
+
+				if (legacyKey != null) {
+					return legacyKey;
+				}
+			}
+
+			return identifier.toString();
+		});
+	}
+
+	private NamespacedIdentifier constructIdentifier(String legacyKey) {
+		return this.legacyKeys.inverse().computeIfAbsent(legacyKey, key -> {
+			String identifier = VanillaEntityTypes.IDENTIFIERS.get(legacyKey);
+
+			if (identifier != null) {
+				return NamespacedIdentifiers.from(identifier);
+			}
+
+			StringBuilder sb = new StringBuilder();
+
+			// convert PascalCase to snake_case
+			for (int i = 0; i < legacyKey.length(); i++) {
+				char chr = legacyKey.charAt(i);
+
+				if (Character.isUpperCase(chr)) {
+					chr = Character.toLowerCase(chr);
+
+					if (i != 0) {
+						sb.append('_');
+					}
+				}
+
+				sb.append(chr);
+			}
+
+			return NamespacedIdentifiers.from(sb.toString());
+		});
+	}
+
+	public Class<? extends Entity> get(String legacyKey) {
+		NamespacedIdentifier identifier = this.legacyKeys.inverse().get(legacyKey);
+		return identifier == null ? null : this.get(identifier);
+	}
+
+	public String getLegacyKey(Class<? extends Entity> type) {
+		NamespacedIdentifier identifier = this.getIdentifier(type);
+		return identifier == null ? null : this.legacyKeys.get(identifier);
+	}
+
+	public Set<String> legacyKeySet() {
+		return this.legacyKeys.values();
+	}
+
+	@Override
+	public void clear() {
+		super.clear();
+
+		Entities.KEY_TO_TYPE.clear();
+		Entities.TYPE_TO_KEY.clear();
+		if (VANILLA_TRACKS_IDS) {
+			Entities.ID_TO_TYPE.clear();
+			Entities.TYPE_TO_ID.clear();
+		}
+	}
+}
diff --git a/libraries/entities/entities-mca1.0.1_01-mc11w48a/src/main/java/net/ornithemc/osl/entities/impl/mixin/common/EntitiesMixin.java b/libraries/entities/entities-mca1.0.1_01-mc11w48a/src/main/java/net/ornithemc/osl/entities/impl/mixin/common/EntitiesMixin.java
new file mode 100644
index 00000000..c7c89dff
--- /dev/null
+++ b/libraries/entities/entities-mca1.0.1_01-mc11w48a/src/main/java/net/ornithemc/osl/entities/impl/mixin/common/EntitiesMixin.java
@@ -0,0 +1,34 @@
+package net.ornithemc.osl.entities.impl.mixin.common;
+
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
+
+import net.minecraft.entity.Entities;
+
+import net.ornithemc.osl.entities.impl.EntityTypeRegistryImpl;
+
+@Mixin(Entities.class)
+public class EntitiesMixin {
+
+	@Inject(
+		method = "<clinit>",
+		at = @At(
+			value = "HEAD"
+		)
+	)
+	private static void osl$entities$unlockEntityTypeRegistry(CallbackInfo ci) {
+		EntityTypeRegistryImpl.unlock();
+	}
+
+	@Inject(
+		method = "<clinit>",
+		at = @At(
+			value = "TAIL"
+		)
+	)
+	private static void osl$entities$registerEntityTypes(CallbackInfo ci) {
+		EntityTypeRegistryImpl.registerEntityTypes();
+	}
+}
diff --git a/libraries/entities/entities-mca1.0.1_01-mc11w48a/src/main/java/net/ornithemc/osl/entities/impl/mixin/common/EntitiesMixinNew.java b/libraries/entities/entities-mca1.0.1_01-mc11w48a/src/main/java/net/ornithemc/osl/entities/impl/mixin/common/EntitiesMixinNew.java
new file mode 100644
index 00000000..f256d352
--- /dev/null
+++ b/libraries/entities/entities-mca1.0.1_01-mc11w48a/src/main/java/net/ornithemc/osl/entities/impl/mixin/common/EntitiesMixinNew.java
@@ -0,0 +1,25 @@
+package net.ornithemc.osl.entities.impl.mixin.common;
+
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
+
+import net.minecraft.entity.Entities;
+import net.minecraft.entity.Entity;
+
+import net.ornithemc.osl.entities.impl.EntityTypeRegistryImpl;
+
+@Mixin(Entities.class)
+public class EntitiesMixinNew {
+
+	@Inject(
+		method = "register",
+		at = @At(
+			value = "TAIL"
+		)
+	)
+	private static void osl$entities$register(Class<? extends Entity> type, String legacyKey, int id, CallbackInfo ci) {
+		EntityTypeRegistryImpl.REGISTRY.register(id, legacyKey, type);
+	}
+}
diff --git a/libraries/entities/entities-mca1.0.1_01-mc11w48a/src/main/java/net/ornithemc/osl/entities/impl/mixin/common/EntitiesMixinOld.java b/libraries/entities/entities-mca1.0.1_01-mc11w48a/src/main/java/net/ornithemc/osl/entities/impl/mixin/common/EntitiesMixinOld.java
new file mode 100644
index 00000000..e762afe4
--- /dev/null
+++ b/libraries/entities/entities-mca1.0.1_01-mc11w48a/src/main/java/net/ornithemc/osl/entities/impl/mixin/common/EntitiesMixinOld.java
@@ -0,0 +1,27 @@
+package net.ornithemc.osl.entities.impl.mixin.common;
+
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
+
+import com.llamalad7.mixinextras.sugar.Local;
+
+import net.minecraft.entity.Entities;
+import net.minecraft.entity.Entity;
+
+import net.ornithemc.osl.entities.impl.EntityTypeRegistryImpl;
+
+@Mixin(Entities.class)
+public class EntitiesMixinOld {
+
+	@Inject(
+		method = "register",
+		at = @At(
+			value = "TAIL"
+		)
+	)
+	private static void osl$entities$register(CallbackInfo ci, @Local Class<? extends Entity> type, @Local String legacyKey) {
+		EntityTypeRegistryImpl.REGISTRY.register(legacyKey, type);
+	}
+}
diff --git a/libraries/entities/entities-mca1.0.1_01-mc11w48a/src/main/resources/fabric.mod.json b/libraries/entities/entities-mca1.0.1_01-mc11w48a/src/main/resources/fabric.mod.json
new file mode 100644
index 00000000..18fe41a1
--- /dev/null
+++ b/libraries/entities/entities-mca1.0.1_01-mc11w48a/src/main/resources/fabric.mod.json
@@ -0,0 +1,38 @@
+{
+  "schemaVersion": 1,
+  "id": "osl-entities",
+  "version": "0.1.0+mca1.0.1_01-mc11w48a",
+  "environment": "*",
+  "entrypoints": {
+    "init": [
+      "net.ornithemc.osl.entities.impl.EntityTypeRegistryImpl::init"
+    ]
+  },
+  "mixins": [
+    "osl.entities.mixins.json"
+  ],
+  "accessWidener": "osl.entities.classtweaker",
+  "depends": {
+    "fabricloader": "\u003e\u003d0.18.0",
+    "minecraft": "\u003e\u003d1.0.0-alpha.0.1.1 \u003c\u003d1.1-alpha.11.48.a",
+    "osl-core": "\u003e\u003d0.9.0",
+    "osl-entrypoints": "\u003e\u003d0.5.0",
+    "osl-lifecycle-events": "\u003e\u003d0.6.0",
+    "osl-executors": "\u003e\u003d0.1.0",
+    "osl-text-components": "\u003e\u003d0.1.0-",
+    "osl-networking": "\u003e\u003d0.10.0",
+    "osl-networking-impl": "\u003e\u003d0.2.0",
+    "osl-registries": "\u003e\u003d0.1.0"
+  },
+  "name": "OSL Entities",
+  "description": "Entities API and events.",
+  "authors": [
+    "OrnitheMC"
+  ],
+  "contact": {
+    "homepage": "https://ornithemc.net/",
+    "issues": "https://github.com/OrnitheMC/ornithe-standard-libraries/issues",
+    "sources": "https://github.com/OrnitheMC/ornithe-standard-libraries"
+  },
+  "license": "Apache-2.0"
+}
\ No newline at end of file
diff --git a/libraries/entities/entities-mca1.0.1_01-mc11w48a/src/main/resources/osl.entities.classtweaker b/libraries/entities/entities-mca1.0.1_01-mc11w48a/src/main/resources/osl.entities.classtweaker
new file mode 100644
index 00000000..331f2be2
--- /dev/null
+++ b/libraries/entities/entities-mca1.0.1_01-mc11w48a/src/main/resources/osl.entities.classtweaker
@@ -0,0 +1,7 @@
+classTweaker	v1	named
+
+accessible	field	net/minecraft/entity/Entities	KEY_TO_TYPE	Ljava/util/Map;
+accessible	field	net/minecraft/entity/Entities	TYPE_TO_KEY	Ljava/util/Map;
+accessible	field	net/minecraft/entity/Entities	ID_TO_TYPE	Ljava/util/Map;
+accessible	field	net/minecraft/entity/Entities	TYPE_TO_ID	Ljava/util/Map;
+
diff --git a/libraries/entities/entities-mca1.0.1_01-mc11w48a/src/main/resources/osl.entities.mixins.json b/libraries/entities/entities-mca1.0.1_01-mc11w48a/src/main/resources/osl.entities.mixins.json
new file mode 100644
index 00000000..6f4295a5
--- /dev/null
+++ b/libraries/entities/entities-mca1.0.1_01-mc11w48a/src/main/resources/osl.entities.mixins.json
@@ -0,0 +1,19 @@
+{
+	"required": true,
+	"minVersion": "0.8",
+	"package": "net.ornithemc.osl.entities.impl.mixin",
+	"compatibilityLevel": "JAVA_8",
+	"plugin": "net.ornithemc.osl.entities.impl.EntitiesMixinPlugin",
+	"mixins": [
+		"common.EntitiesMixin",
+		"common.EntitiesMixinNew",
+		"common.EntitiesMixinOld"
+	],
+	"client": [
+	],
+	"server": [
+	],
+	"injectors": {
+		"defaultRequire": 1
+	}
+}
diff --git a/libraries/entities/gradle.properties b/libraries/entities/gradle.properties
new file mode 100644
index 00000000..aeb2dc27
--- /dev/null
+++ b/libraries/entities/gradle.properties
@@ -0,0 +1,7 @@
+library_id = entities
+library_name = Entities
+library_description = Entities API and events.
+library_version = 0.1.0
+
+entrypoint_init = net.ornithemc.osl.entities.impl.EntityTypeRegistryImpl::init
+osl_dependencies = core:0.9.0,entrypoints:0.5.0,registries:0.1.0
diff --git a/libraries/registries/registries-mc12w18a-mc1.6.4/src/main/java/net/ornithemc/osl/registries/api/registry/RegistryKeys.java b/libraries/registries/registries-mc12w18a-mc1.6.4/src/main/java/net/ornithemc/osl/registries/api/registry/RegistryKeys.java
index 87d5b78a..5479e0b7 100644
--- a/libraries/registries/registries-mc12w18a-mc1.6.4/src/main/java/net/ornithemc/osl/registries/api/registry/RegistryKeys.java
+++ b/libraries/registries/registries-mc12w18a-mc1.6.4/src/main/java/net/ornithemc/osl/registries/api/registry/RegistryKeys.java
@@ -1,6 +1,7 @@
 package net.ornithemc.osl.registries.api.registry;
 
 import net.minecraft.block.Block;
+import net.minecraft.entity.Entity;
 import net.minecraft.item.Item;
 
 import net.ornithemc.osl.core.api.util.NamespacedIdentifier;
@@ -15,6 +16,7 @@ public final class RegistryKeys {
 
 	public static final ResourceKey<Registry<Block>> BLOCK = from("block");
 	public static final ResourceKey<Registry<Item>> ITEM = from("item");
+	public static final ResourceKey<Registry<Class<? extends Entity>>> ENTITY_TYPE = from("entity_type");
 
 	/**
 	 * Constructs a registry key with the default namespace and the given identifier.
diff --git a/libraries/registries/registries-mc13w36a-mc14w26c/src/main/java/net/ornithemc/osl/registries/api/registry/RegistryKeys.java b/libraries/registries/registries-mc13w36a-mc14w26c/src/main/java/net/ornithemc/osl/registries/api/registry/RegistryKeys.java
index 87d5b78a..5479e0b7 100644
--- a/libraries/registries/registries-mc13w36a-mc14w26c/src/main/java/net/ornithemc/osl/registries/api/registry/RegistryKeys.java
+++ b/libraries/registries/registries-mc13w36a-mc14w26c/src/main/java/net/ornithemc/osl/registries/api/registry/RegistryKeys.java
@@ -1,6 +1,7 @@
 package net.ornithemc.osl.registries.api.registry;
 
 import net.minecraft.block.Block;
+import net.minecraft.entity.Entity;
 import net.minecraft.item.Item;
 
 import net.ornithemc.osl.core.api.util.NamespacedIdentifier;
@@ -15,6 +16,7 @@ public final class RegistryKeys {
 
 	public static final ResourceKey<Registry<Block>> BLOCK = from("block");
 	public static final ResourceKey<Registry<Item>> ITEM = from("item");
+	public static final ResourceKey<Registry<Class<? extends Entity>>> ENTITY_TYPE = from("entity_type");
 
 	/**
 	 * Constructs a registry key with the default namespace and the given identifier.
diff --git a/libraries/registries/registries-mc14w27a-mc17w46a/src/main/java/net/ornithemc/osl/registries/api/registry/RegistryKeys.java b/libraries/registries/registries-mc14w27a-mc17w46a/src/main/java/net/ornithemc/osl/registries/api/registry/RegistryKeys.java
index 87d5b78a..5479e0b7 100644
--- a/libraries/registries/registries-mc14w27a-mc17w46a/src/main/java/net/ornithemc/osl/registries/api/registry/RegistryKeys.java
+++ b/libraries/registries/registries-mc14w27a-mc17w46a/src/main/java/net/ornithemc/osl/registries/api/registry/RegistryKeys.java
@@ -1,6 +1,7 @@
 package net.ornithemc.osl.registries.api.registry;
 
 import net.minecraft.block.Block;
+import net.minecraft.entity.Entity;
 import net.minecraft.item.Item;
 
 import net.ornithemc.osl.core.api.util.NamespacedIdentifier;
@@ -15,6 +16,7 @@ public final class RegistryKeys {
 
 	public static final ResourceKey<Registry<Block>> BLOCK = from("block");
 	public static final ResourceKey<Registry<Item>> ITEM = from("item");
+	public static final ResourceKey<Registry<Class<? extends Entity>>> ENTITY_TYPE = from("entity_type");
 
 	/**
 	 * Constructs a registry key with the default namespace and the given identifier.
diff --git a/libraries/registries/registries-mc17w47a-mc18w31a/src/main/java/net/ornithemc/osl/registries/api/registry/RegistryKeys.java b/libraries/registries/registries-mc17w47a-mc18w31a/src/main/java/net/ornithemc/osl/registries/api/registry/RegistryKeys.java
index 87d5b78a..3414b1bd 100644
--- a/libraries/registries/registries-mc17w47a-mc18w31a/src/main/java/net/ornithemc/osl/registries/api/registry/RegistryKeys.java
+++ b/libraries/registries/registries-mc17w47a-mc18w31a/src/main/java/net/ornithemc/osl/registries/api/registry/RegistryKeys.java
@@ -1,6 +1,7 @@
 package net.ornithemc.osl.registries.api.registry;
 
 import net.minecraft.block.Block;
+import net.minecraft.entity.EntityType;
 import net.minecraft.item.Item;
 
 import net.ornithemc.osl.core.api.util.NamespacedIdentifier;
@@ -15,6 +16,7 @@ public final class RegistryKeys {
 
 	public static final ResourceKey<Registry<Block>> BLOCK = from("block");
 	public static final ResourceKey<Registry<Item>> ITEM = from("item");
+	public static final ResourceKey<Registry<EntityType<?>>> ENTITY_TYPE = from("entity_type");
 
 	/**
 	 * Constructs a registry key with the default namespace and the given identifier.
diff --git a/libraries/registries/registries-mc18w32a-mc1.13.2/src/main/java/net/ornithemc/osl/registries/api/registry/RegistryKeys.java b/libraries/registries/registries-mc18w32a-mc1.13.2/src/main/java/net/ornithemc/osl/registries/api/registry/RegistryKeys.java
index 87d5b78a..3414b1bd 100644
--- a/libraries/registries/registries-mc18w32a-mc1.13.2/src/main/java/net/ornithemc/osl/registries/api/registry/RegistryKeys.java
+++ b/libraries/registries/registries-mc18w32a-mc1.13.2/src/main/java/net/ornithemc/osl/registries/api/registry/RegistryKeys.java
@@ -1,6 +1,7 @@
 package net.ornithemc.osl.registries.api.registry;
 
 import net.minecraft.block.Block;
+import net.minecraft.entity.EntityType;
 import net.minecraft.item.Item;
 
 import net.ornithemc.osl.core.api.util.NamespacedIdentifier;
@@ -15,6 +16,7 @@ public final class RegistryKeys {
 
 	public static final ResourceKey<Registry<Block>> BLOCK = from("block");
 	public static final ResourceKey<Registry<Item>> ITEM = from("item");
+	public static final ResourceKey<Registry<EntityType<?>>> ENTITY_TYPE = from("entity_type");
 
 	/**
 	 * Constructs a registry key with the default namespace and the given identifier.
diff --git a/libraries/registries/registries-mc18w43a-mc19w03c/src/main/java/net/ornithemc/osl/registries/api/registry/RegistryKeys.java b/libraries/registries/registries-mc18w43a-mc19w03c/src/main/java/net/ornithemc/osl/registries/api/registry/RegistryKeys.java
index 87d5b78a..3414b1bd 100644
--- a/libraries/registries/registries-mc18w43a-mc19w03c/src/main/java/net/ornithemc/osl/registries/api/registry/RegistryKeys.java
+++ b/libraries/registries/registries-mc18w43a-mc19w03c/src/main/java/net/ornithemc/osl/registries/api/registry/RegistryKeys.java
@@ -1,6 +1,7 @@
 package net.ornithemc.osl.registries.api.registry;
 
 import net.minecraft.block.Block;
+import net.minecraft.entity.EntityType;
 import net.minecraft.item.Item;
 
 import net.ornithemc.osl.core.api.util.NamespacedIdentifier;
@@ -15,6 +16,7 @@ public final class RegistryKeys {
 
 	public static final ResourceKey<Registry<Block>> BLOCK = from("block");
 	public static final ResourceKey<Registry<Item>> ITEM = from("item");
+	public static final ResourceKey<Registry<EntityType<?>>> ENTITY_TYPE = from("entity_type");
 
 	/**
 	 * Constructs a registry key with the default namespace and the given identifier.
diff --git a/libraries/registries/registries-mc19w04a-mc1.14.4/src/main/java/net/ornithemc/osl/registries/api/registry/RegistryKeys.java b/libraries/registries/registries-mc19w04a-mc1.14.4/src/main/java/net/ornithemc/osl/registries/api/registry/RegistryKeys.java
index 87d5b78a..3414b1bd 100644
--- a/libraries/registries/registries-mc19w04a-mc1.14.4/src/main/java/net/ornithemc/osl/registries/api/registry/RegistryKeys.java
+++ b/libraries/registries/registries-mc19w04a-mc1.14.4/src/main/java/net/ornithemc/osl/registries/api/registry/RegistryKeys.java
@@ -1,6 +1,7 @@
 package net.ornithemc.osl.registries.api.registry;
 
 import net.minecraft.block.Block;
+import net.minecraft.entity.EntityType;
 import net.minecraft.item.Item;
 
 import net.ornithemc.osl.core.api.util.NamespacedIdentifier;
@@ -15,6 +16,7 @@ public final class RegistryKeys {
 
 	public static final ResourceKey<Registry<Block>> BLOCK = from("block");
 	public static final ResourceKey<Registry<Item>> ITEM = from("item");
+	public static final ResourceKey<Registry<EntityType<?>>> ENTITY_TYPE = from("entity_type");
 
 	/**
 	 * Constructs a registry key with the default namespace and the given identifier.
diff --git a/libraries/registries/registries-mca1.0.1_01-mc12w17a/src/main/java/net/ornithemc/osl/registries/api/registry/RegistryKeys.java b/libraries/registries/registries-mca1.0.1_01-mc12w17a/src/main/java/net/ornithemc/osl/registries/api/registry/RegistryKeys.java
index 87d5b78a..5479e0b7 100644
--- a/libraries/registries/registries-mca1.0.1_01-mc12w17a/src/main/java/net/ornithemc/osl/registries/api/registry/RegistryKeys.java
+++ b/libraries/registries/registries-mca1.0.1_01-mc12w17a/src/main/java/net/ornithemc/osl/registries/api/registry/RegistryKeys.java
@@ -1,6 +1,7 @@
 package net.ornithemc.osl.registries.api.registry;
 
 import net.minecraft.block.Block;
+import net.minecraft.entity.Entity;
 import net.minecraft.item.Item;
 
 import net.ornithemc.osl.core.api.util.NamespacedIdentifier;
@@ -15,6 +16,7 @@ public final class RegistryKeys {
 
 	public static final ResourceKey<Registry<Block>> BLOCK = from("block");
 	public static final ResourceKey<Registry<Item>> ITEM = from("item");
+	public static final ResourceKey<Registry<Class<? extends Entity>>> ENTITY_TYPE = from("entity_type");
 
 	/**
 	 * Constructs a registry key with the default namespace and the given identifier.
diff --git a/settings.gradle b/settings.gradle
index e53df069..fd5cd679 100644
--- a/settings.gradle
+++ b/settings.gradle
@@ -46,6 +46,19 @@ include ':libraries:config:config-mc14w27a-mc15w39c'
 include ':libraries:config:config-mc15w40a-mc1.12.2'
 include ':libraries:config:config-mc17w43a-mc1.13.2'
 
+include ':libraries:entities'
+include ':libraries:entities:entities-mca1.0.1_01-mc11w48a'
+include ':libraries:entities:entities-mc12w01a-mc1.8.2-pre4'
+include ':libraries:entities:entities-mc1.8.2-pre5-mc1.10.2'
+include ':libraries:entities:entities-mc16w32a-mc18w01a'
+include ':libraries:entities:entities-mc18w19a-mc18w31a'
+include ':libraries:entities:entities-mc18w32a-mc19w04b'
+include ':libraries:entities:entities-mc19w08a-mc1.14.4'
+
+include ':libraries:entities-rendering'
+include ':libraries:entities-rendering:entities-rendering-mca1.0.1_01-mc14w04b'
+include ':libraries:entities-rendering:entities-rendering-mc14w05a-mc1.14.4'
+
 include ':libraries:entrypoints'
 include ':libraries:entrypoints:entrypoints-mcin-20091223-1459-mc1.5.2'
 include ':libraries:entrypoints:entrypoints-mc13w16a-mc1.14.4'