Zombies are good, but you GOTTA have mutants of some kind (lickers, hunters, tyrants, etc.) Try the Strong Zombie, he has a deadly arm, ribcage exposed, falling out guts and maggots. He is a genetically-engineered super-creature who can beat the player down in seconds.
Features: Fully rigged, textured and animated. Animated maggots. Unity package, FBX format (exported and tested with Unity), MAX format for customizing. Other formats: b3d (Blitz3d), dbo, ugh (fragMotion), dae (OpenCollada), blend (Blender), mdl (3DGameStudio), smd, x, mesh-skel-mtrl-gfx-anim (Esenthel), iAvatar-iMotion (iClone 5) Animations: walk, run, stand, idle, attack 1, attack 2, attack 3, hit 1, hit 2, death View animations at: youtube(dot)com/watch?v=vWG0RDeA5ak