Okay, because I have no idea whatsoever of coding and things and stuffs, I am unable to make this mod. Therefore, I will suggest it.
My idea is basically really versions of mobs, born from the lightning struck bodies of Zombies, Skeletons, Spiders, and Enderman. Creepers, I think, would be "Adminified" (?) when they become charged creepers. They should all be 1.5 times the size of their less powerful counterparts, and have a new attack along with their normal attacks.
Perhaps a Zombie Horseman? Ender Giant (who explodes the ground when teleporting)? Tarantula? Skeletal Centaur? I don`t know. Anyway, I just think this would make a cool mod, similar to the Mutant Creatures Mod, with super cool and powerful mobs.