In Norse mythology and Scandinavian folklore, an undead creature that guards its burial mound and possesses superhuman strength is a draugr.
A draugr is a corporeal revenant: unlike a purely ghostly spirit, it has an animated physical body. In Icelandic sagas, draugar may remain in graves or burial mounds, often protecting treasure and attacking trespassers. The related term haugbúi more specifically means a mound-dweller that stays near its tomb.
These revenants are commonly associated with greed, envy, decay, and hostility toward the living. Tales describe them as corpse-pale or death-blue, foul-smelling, and enormously strong. Some can also change size, shapeshift, or create darkness, making them more than simple reanimated corpses.
Modern games and films often depict draugar as mummified Viking zombies, but the older stories are more varied. Heroes may need to wrestle one, cut off its head, burn the body, or scatter its remains to ensure a “second death.”