craftbukkit/nms-patches/net/minecraft/world/entity/projectile/EntityEgg.patch

--- a/net/minecraft/world/entity/projectile/EntityEgg.java
+++ b/net/minecraft/world/entity/projectile/EntityEgg.java
@@ -12,6 +12,15 @@
 import net.minecraft.world.phys.MovingObjectPosition;
 import net.minecraft.world.phys.MovingObjectPositionEntity;
 
+// CraftBukkit start
+import net.minecraft.server.level.EntityPlayer;
+import net.minecraft.world.entity.Entity;
+import org.bukkit.entity.Ageable;
+import org.bukkit.entity.EntityType;
+import org.bukkit.entity.Player;
+import org.bukkit.event.player.PlayerEggThrowEvent;
+// CraftBukkit end
+
 public class EntityEgg extends EntityProjectileThrowable {
 
     public EntityEgg(EntityTypes<? extends EntityEgg> entitytypes, World world) {
@@ -48,20 +57,40 @@
     protected void onHit(MovingObjectPosition movingobjectposition) {
         super.onHit(movingobjectposition);
         if (!this.level.isClientSide) {
-            if (this.random.nextInt(8) == 0) {
+            boolean hatching = this.random.nextInt(8) == 0; // CraftBukkit
+            if (true) {
                 byte b0 = 1;
 
                 if (this.random.nextInt(32) == 0) {
                     b0 = 4;
                 }
 
-                for (int i = 0; i < b0; ++i) {
-                    EntityChicken entitychicken = (EntityChicken) EntityTypes.CHICKEN.create(this.level);
+                // CraftBukkit start
+                if (!hatching) {
+                    b0 = 0;
+                }
+                EntityType hatchingType = EntityType.CHICKEN;
+
+                Entity shooter = this.getOwner();
+                if (shooter instanceof EntityPlayer) {
+                    PlayerEggThrowEvent event = new PlayerEggThrowEvent((Player) shooter.getBukkitEntity(), (org.bukkit.entity.Egg) this.getBukkitEntity(), hatching, b0, hatchingType);
+                    this.level.getCraftServer().getPluginManager().callEvent(event);
+
+                    b0 = event.getNumHatches();
+                    hatching = event.isHatching();
+                    hatchingType = event.getHatchingType();
+                }
 
-                    entitychicken.setAge(-24000);
-                    entitychicken.moveTo(this.getX(), this.getY(), this.getZ(), this.getYRot(), 0.0F);
-                    this.level.addFreshEntity(entitychicken);
+                if (hatching) {
+                    for (int i = 0; i < b0; ++i) {
+                        Entity entity = level.getWorld().createEntity(new org.bukkit.Location(level.getWorld(), this.getX(), this.getY(), this.getZ(), this.getYRot(), 0.0F), hatchingType.getEntityClass());
+                        if (entity.getBukkitEntity() instanceof Ageable) {
+                            ((Ageable) entity.getBukkitEntity()).setBaby();
+                        }
+                        level.getWorld().addEntity(entity, org.bukkit.event.entity.CreatureSpawnEvent.SpawnReason.EGG);
+                    }
                 }
+                // CraftBukkit end
             }
 
             this.level.broadcastEntityEvent(this, (byte) 3);