You should create this mod because people may want a mutant Blaze, or Spider, so here's what I think: -Mutant Blaze: Has 25 harts of health and will drop Blaze Rods(4-7), and will drop a Blaze Sword, and Blaze Flares(1-2). Shoots fireballs. Has 2 heads. -Mutant Spider:Haze 3 heads and will make spiderwebs wherever it goes. It will Drop spider eyes(5-6), and will drop a spider head. Has 25 harts of health -Mutant Wither Skeleton: Will have 1 head and has 2 stone swords. Will drop Wither Skulls(1-3), and a Wither sword(craftable). Has 30 harts of health. (See crafting recipe down below) -Phoenix(Secret Mob): Only craftable. Has 120 harts of health, and can be rideable if spawned by Blaze Flares. Hard to beat Crafting S=Sticks B-Blaze Flares WS=Wither Skulls Wither Sword W W W S S Phoenix Spawner B B B B W B B B B Hopefully you get the idea, come up what the end product of the recipes will look like, please, this would be a big help to me.
EnderBlaze You are asking for mods, adding heads to an mob is impossible with bukkit, just like adding an new one. And mobs only have one weapon slot
This is impossible to do, that is a mod and we are creating plugins. Plugins can not add things into the game, they can only manipulate what is already there.
