Vengeance deities

spirit of a dead person who returns from the afterlife to seek revenge

In Akkadian and Sumerian mythology, Alû is a vengeful spirit of the Utukku that goes down to the underworld Kur. The demon has no mouth, lips or ears. It would roam at night and terrifies people while they sleep and the Alû may also torment their victims for fun. It was also said that possession by the Alû would result in unconsciousness or a coma; in this manner it resembles creatures such as the mara, and incubus, which are invoked to explain sleep paralysis. In Akkadian and Sumerian mythology, it is associated with other demons such as the Gallu and the Lilu.