The idea of the undead -- the physical return from the grave of a dead person or animal -- is one of very few monsters that can be considered universal, as almost all cultures on Earth have some concept of the problem. Like ghosts, the undead are probably one of the oldest monsters to be believed in worldwide for both monsters take one of the ultimate fears and unknowns of human existence -- the end of life -- and step upon the one part of it that humans fully understand: the dead do not return.

        While there are many fictional tales regarding various types of undead, such as vampires and zombies, actual reports are rare... and generally describe a very different set of monstrous behaviors and expectations.