The undead are beings in mythology, legend, or fiction that are deceased but behave as if alive. Most commonly the term refers to corporeal forms of formerly alive humans, such as mummies, vampires, and zombies, which have been reanimated by supernatural means, technology, or disease. In some cases, the term also includes incorporeal forms of the dead, such as ghosts.
The Ghost of Barbara Radziwiłł by Wojciech Gerson. Ghosts are a common form of the undead.
The Dead Lovers, ca. 1470 (Strasbourg, Musée de l'Œuvre Notre-Dame)
Utagawa Yoshiiku, Specter frightening a young woman
Mummies are commonly featured in horror genres as undead creatures wrapped in bandages. Similar undead include skeletons and zombies.
An illustration by Martin van Maële of the mummy from "Lot No. 249" an 1892 Gothic horror short story by British writer Arthur Conan Doyle.