diff --git a/src/main/java/net/minecraft/server/EntityPotion.java b/src/main/java/net/minecraft/server/EntityPotion.java
index 8a6241b8d8..884b052cc9 100644
--- a/src/main/java/net/minecraft/server/EntityPotion.java
+++ b/src/main/java/net/minecraft/server/EntityPotion.java
@@ -66,7 +66,7 @@ public class EntityPotion extends EntityProjectile {
                                 int i = mobeffect.getEffectId();
 
                                 if (MobEffectList.byId[i].b()) {
-                                    MobEffectList.byId[i].a(this.shooter, (EntityLiving) entity, mobeffect.getAmplifier(), d1);
+                                    MobEffectList.byId[i].a(this.shooter, (EntityLiving) entity, mobeffect.getAmplifier(), d1, this); // CraftBukkit - added 'this'
                                 } else {
                                     int j = (int) (d1 * (double) mobeffect.getDuration() + 0.5D);
 
diff --git a/src/main/java/net/minecraft/server/MobEffectList.java b/src/main/java/net/minecraft/server/MobEffectList.java
new file mode 100644
index 0000000000..dea14775e0
--- /dev/null
+++ b/src/main/java/net/minecraft/server/MobEffectList.java
@@ -0,0 +1,187 @@
+package net.minecraft.server;
+
+// CraftBukkit start
+import org.bukkit.Bukkit;
+import org.bukkit.craftbukkit.event.CraftEventFactory;
+import org.bukkit.event.entity.EntityDamageEvent;
+import org.bukkit.event.entity.EntityDamageEvent.DamageCause;
+import org.bukkit.event.entity.EntityRegainHealthEvent.RegainReason;
+// CraftBukkit end
+
+public class MobEffectList {
+
+    public static final MobEffectList[] byId = new MobEffectList[32];
+    public static final MobEffectList b = null;
+    public static final MobEffectList FASTER_MOVEMENT = (new MobEffectList(1, false, 8171462)).a("potion.moveSpeed").a(0, 0);
+    public static final MobEffectList SLOWER_MOVEMENT = (new MobEffectList(2, true, 5926017)).a("potion.moveSlowdown").a(1, 0);
+    public static final MobEffectList FASTER_DIG = (new MobEffectList(3, false, 14270531)).a("potion.digSpeed").a(2, 0).a(1.5D);
+    public static final MobEffectList SLOWER_DIG = (new MobEffectList(4, true, 4866583)).a("potion.digSlowDown").a(3, 0);
+    public static final MobEffectList INCREASE_DAMAGE = (new MobEffectList(5, false, 9643043)).a("potion.damageBoost").a(4, 0);
+    public static final MobEffectList HEAL = (new InstantMobEffect(6, false, 16262179)).a("potion.heal");
+    public static final MobEffectList HARM = (new InstantMobEffect(7, true, 4393481)).a("potion.harm");
+    public static final MobEffectList JUMP = (new MobEffectList(8, false, 7889559)).a("potion.jump").a(2, 1);
+    public static final MobEffectList CONFUSION = (new MobEffectList(9, true, 5578058)).a("potion.confusion").a(3, 1).a(0.25D);
+    public static final MobEffectList REGENERATION = (new MobEffectList(10, false, 13458603)).a("potion.regeneration").a(7, 0).a(0.25D);
+    public static final MobEffectList RESISTANCE = (new MobEffectList(11, false, 10044730)).a("potion.resistance").a(6, 1);
+    public static final MobEffectList FIRE_RESISTANCE = (new MobEffectList(12, false, 14981690)).a("potion.fireResistance").a(7, 1);
+    public static final MobEffectList WATER_BREATHING = (new MobEffectList(13, false, 3035801)).a("potion.waterBreathing").a(0, 2);
+    public static final MobEffectList INVISIBILITY = (new MobEffectList(14, false, 8356754)).a("potion.invisibility").a(0, 1).e();
+    public static final MobEffectList BLINDNESS = (new MobEffectList(15, true, 2039587)).a("potion.blindness").a(5, 1).a(0.25D);
+    public static final MobEffectList NIGHT_VISION = (new MobEffectList(16, false, 2039713)).a("potion.nightVision").a(4, 1).e();
+    public static final MobEffectList HUNGER = (new MobEffectList(17, true, 5797459)).a("potion.hunger").a(1, 1);
+    public static final MobEffectList WEAKNESS = (new MobEffectList(18, true, 4738376)).a("potion.weakness").a(5, 0);
+    public static final MobEffectList POISON = (new MobEffectList(19, true, 5149489)).a("potion.poison").a(6, 0).a(0.25D);
+    public static final MobEffectList v = null;
+    public static final MobEffectList w = null;
+    public static final MobEffectList x = null;
+    public static final MobEffectList y = null;
+    public static final MobEffectList z = null;
+    public static final MobEffectList A = null;
+    public static final MobEffectList B = null;
+    public static final MobEffectList C = null;
+    public static final MobEffectList D = null;
+    public static final MobEffectList E = null;
+    public static final MobEffectList F = null;
+    public static final MobEffectList G = null;
+    public final int id;
+    private String I = "";
+    private int J = -1;
+    private final boolean K;
+    private double L;
+    private boolean M;
+    private final int N;
+
+    protected MobEffectList(int i, boolean flag, int j) {
+        this.id = i;
+        byId[i] = this;
+        this.K = flag;
+        if (flag) {
+            this.L = 0.5D;
+        } else {
+            this.L = 1.0D;
+        }
+
+        this.N = j;
+    }
+
+    protected MobEffectList a(int i, int j) {
+        this.J = i + j * 8;
+        return this;
+    }
+
+    public int getId() {
+        return this.id;
+    }
+
+    public void tick(EntityLiving entityliving, int i) {
+        if (this.id == REGENERATION.id) {
+            if (entityliving.getHealth() < entityliving.getMaxHealth()) {
+                entityliving.heal(1, RegainReason.MAGIC_REGEN); // CraftBukkit
+            }
+        } else if (this.id == POISON.id) {
+            if (entityliving.getHealth() > 1) {
+                // CraftBukkit start
+                EntityDamageEvent event = CraftEventFactory.callEntityDamageEvent(null, (EntityLiving) entityliving.getBukkitEntity(), DamageCause.POISON, 1);
+                Bukkit.getPluginManager().callEvent(event);
+
+                if (!event.isCancelled() && event.getDamage() > 0) {
+                    entityliving.damageEntity(DamageSource.MAGIC, event.getDamage());
+                }
+                // CraftBukkit end
+            }
+        } else if (this.id == HUNGER.id && entityliving instanceof EntityHuman) {
+            ((EntityHuman) entityliving).c(0.025F * (float) (i + 1));
+        } else if ((this.id != HEAL.id || entityliving.aE()) && (this.id != HARM.id || !entityliving.aE())) {
+            if (this.id == HARM.id && !entityliving.aE() || this.id == HEAL.id && entityliving.aE()) {
+                // CraftBukkit start
+                EntityDamageEvent event = CraftEventFactory.callEntityDamageEvent(null, (EntityLiving) entityliving.getBukkitEntity(), DamageCause.MAGIC, 6 << i);
+                Bukkit.getPluginManager().callEvent(event);
+
+                if (!event.isCancelled() && event.getDamage() > 0) {
+                    entityliving.damageEntity(DamageSource.MAGIC, event.getDamage());
+                }
+                // CraftBukkit end
+            }
+        } else {
+            entityliving.heal(6 << i, RegainReason.MAGIC); // CraftBukkit
+        }
+    }
+
+    public void a(EntityLiving entityliving, EntityLiving entityliving1, int i, double d0) {
+        // CraftBukkit start - delegate; we need EntityPotion
+        a(entityliving, entityliving1, i, d0, null);
+    }
+
+    public void a(EntityLiving entityliving, EntityLiving entityliving1, int i, double d0, EntityPotion potion) {
+        // CraftBukkit end
+        int j;
+
+        if ((this.id != HEAL.id || entityliving1.aE()) && (this.id != HARM.id || !entityliving1.aE())) {
+            if (this.id == HARM.id && !entityliving1.aE() || this.id == HEAL.id && entityliving1.aE()) {
+                j = (int) (d0 * (double) (6 << i) + 0.5D);
+
+                // CraftBukkit start
+                EntityDamageEvent event = CraftEventFactory.callEntityDamageEvent(potion != null ? potion : entityliving, entityliving1, DamageCause.MAGIC, j);
+                j = event.getDamage();
+                if (event.isCancelled() || j == 0) {
+                    return;
+                }
+                // CraftBukkit end
+
+                if (entityliving == null) {
+                    entityliving1.damageEntity(DamageSource.MAGIC, j);
+                } else {
+                    entityliving1.damageEntity(DamageSource.b(entityliving1, entityliving), j);
+                }
+            }
+        } else {
+            j = (int) (d0 * (double) (6 << i) + 0.5D);
+            entityliving1.heal(j, RegainReason.MAGIC); // CraftBukkit
+        }
+    }
+
+    public boolean b() {
+        return false;
+    }
+
+    public boolean b(int i, int j) {
+        if (this.id != REGENERATION.id && this.id != POISON.id) {
+            return this.id == HUNGER.id;
+        } else {
+            int k = 25 >> j;
+
+            return k > 0 ? i % k == 0 : true;
+        }
+    }
+
+    public MobEffectList a(String s) {
+        this.I = s;
+        return this;
+    }
+
+    public String c() {
+        return this.I;
+    }
+
+    protected MobEffectList a(double d0) {
+        this.L = d0;
+        return this;
+    }
+
+    public double d() {
+        return this.L;
+    }
+
+    public MobEffectList e() {
+        this.M = true;
+        return this;
+    }
+
+    public boolean f() {
+        return this.M;
+    }
+
+    public int g() {
+        return this.N;
+    }
+}
diff --git a/src/main/java/org/bukkit/craftbukkit/event/CraftEventFactory.java b/src/main/java/org/bukkit/craftbukkit/event/CraftEventFactory.java
index be4a5a52e4..cc1518b342 100644
--- a/src/main/java/org/bukkit/craftbukkit/event/CraftEventFactory.java
+++ b/src/main/java/org/bukkit/craftbukkit/event/CraftEventFactory.java
@@ -4,6 +4,7 @@ import java.net.InetAddress;
 import java.util.List;
 
 import net.minecraft.server.ChunkCoordinates;
+import net.minecraft.server.Entity;
 import net.minecraft.server.EntityBlaze;
 import net.minecraft.server.EntityCaveSpider;
 import net.minecraft.server.EntityChicken;
@@ -56,6 +57,7 @@ import org.bukkit.event.Event.Type;
 import org.bukkit.event.block.*;
 import org.bukkit.event.entity.*;
 import org.bukkit.event.entity.CreatureSpawnEvent.SpawnReason;
+import org.bukkit.event.entity.EntityDamageEvent.DamageCause;
 import org.bukkit.event.player.*;
 import org.bukkit.event.server.ServerListPingEvent;
 
@@ -353,4 +355,19 @@ public class CraftEventFactory {
         craftServer.getPluginManager().callEvent(event);
         return event;
     }
+
+    /**
+     * EntityDamage(ByEntityEvent)
+     */
+    public static EntityDamageEvent callEntityDamageEvent(Entity damager, EntityLiving damagee, DamageCause cause, int damage) {
+        EntityDamageEvent event;
+        if (damager != null) {
+            event = new EntityDamageByEntityEvent(damager.getBukkitEntity(), damagee.getBukkitEntity(), cause, damage);
+        } else {
+            event = new EntityDamageEvent(damagee.getBukkitEntity(), cause, damage);
+        }
+        Bukkit.getPluginManager().callEvent(event);
+
+        return event;
+    }
 }