Grace the mutated boar
Grace is a green giant mutated boar found on a farm located in 700N;300W. The very same farm also contain samples of Super Corn.
Grace has a decent health pool comparable to a radiated zombie but it would not attack the player unless attacked first, Infact Grace is the only neutral zombie found in the game.
The place where it is found is a cave that connects to a cage with its name can be read. Killing Grace is essential to completing clear zombie mission.