Undead

The undead are beings in mythology, legend, or fiction that are deceased but behave as if they were alive. A common example of an undead being is a corpse reanimated by supernatural forces, by the application of either the deceased's own life force or that of a supernatural being (such as a demon), or other evil spirits. The undead may be incorporeal (ghosts) or corporeal (mummies, vampires, skeletons, and zombies).

The undead are featured in the belief systems of most cultures, and appear in many works of fantasy and horror fiction. The term is also occasionally used for real-life attempts to resurrect the dead with science and technology, from early experiments like Robert E. Cornish's to future sciences such as "chemical brain preservation" and "cryonics." While the term usually refers to corporeal entities, in some cases (for example, in Dungeons & Dragons), the term also includes incorporeal forms of the dead, such as ghosts.