LUMINOUS: Monsters adds 16 new Zombie / Skeleton variants to the game, each in their own environment! Most of thee 16 variants can be found in my "LUMINOUS : OVERWORLD" mod. but this mod is for those looking to fight these undead foes!
CraftTweaker allows modpacks and servers to customize the game. With CraftTweaker you can change recipes, script events, add new commands and even change item properties!