undead

thumb|The Ghost of Barbara Radziwiłł by [[Wojciech Gerson. Ghosts are a common form of the 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 spirit). The undead may be incorporeal (ghosts) or corporeal (mummies, vampires, skeletons, and zombies).