A common type of undead, a husk that couldn't move on from death. They lack souls, and therefore can't make wishes, how sad. There's many types of them, affecting their bodily properties, such as being weak to sunlight, or having stiff joints, etc etc.
A corpse is either incredibly fragile or long lived, most of them rot or fall apart. But there's lucky bunches who either have properties to preserve them or have medical equipment that help keep their bodies healthy, so all they have to rely on is perserverance.
There!! I wrote you something! Now face me, Zelophehad. This time, I will, I will best you.
P.S. remove this from the guide.