The mare is a damned woman, who is cursed and her body is carried mysteriously during sleep and without her noticing. In this state, she visits villagers to sit on their rib cages while they are asleep, causing them to experience nightmares.

Where did the old hag come from?

A hag, or "the Old Hag", was a nightmare spirit in English and anglophone North American folklore. This variety of hag is essentially identical to the Old English mæra—a being with roots in ancient Germanic superstition, and closely related to the Scandinavian mara.

Has anyone died from sleep paralysis?

- Although there is no denying that sleep paralysis can be a horrifying experience, the truth is there is nothing to be worried about. It doesn't cause any physical harm to the body, and there have been no clinical deaths known till date.