Zombie

A human body, stumbling slowly forward on uncertain legs, possessed with an unstoppable rage.

Zombies are mainly found in cities but also in FEMA camps, while one zombie might only make for a few scratches, a horde can trap you and tear you to smithereens.
There are also ranged variants of zombie, the shocker zombie and the spitter zombie, respectively shooting arcs of electricity and acid at you.

Butcher them to train your survival skill.