In the World of Greyhawk campaign setting for the Dungeons & Dragons roleplaying game, an Animus is an undead monster created through the use of both arcane and divine magic. They are unique to the Great Kingdom and its successor states. Among the most important powers of an animus is its regeneration powers. An animus can only be destroyed totally by being cremated or dissolved in acid. Unique among undead, animi are affected by disease. However, as the animus is already dead, no disease can be fatal or terminal to an animus.