The Undead are generally reanimated corpses or spiritual manifestations, but come in countless varieties and are mostly evil in fiction. They are opposed to the revived that have been brought back to life and restored to their original forms. However, some can be both as they overlap.

Undead beings include:

• Noncorporeals: Spirits roaming the living world after violent and/or untimely deaths. Their purposes are usually to haunt their enemies and seek vengeance on them; for more information read the ghostly criteria.
• Zombies: Living corpses created via magic, science and/or being bitten by other zombies. To survive they eat the internal organs of living beings (e.g. Creeper, Colonel America).
• Skeletons: The representation of the human body's innermost structure. Similar to zombies, they can reattach body parts. They are also associated with the Day of the Dead.
• Vampires: Literal bloodsuckers with pale skin, sharp teeth and superhuman abilities. They do not appear in or have reflections. They can killed by garlic, bright lights or a wooden stake to the heart (e.g. Count Dracula, Count Orlok, Volturi).
• Mummies: Similar to zombies and skeletons, but having been subjected to mummification by removing their intestines and wrapping them in bandages. Mostly associated with ancient Egypt.
• Liches: Individuals who become undead in their desires to obtain immortality and usually the one responsible for the existence of the undead. They are usually depicted as cloaked and hooded skeletons (e.g. the Lich, Horned King, Skeletor, Imhotep).