Throughout history and throughout the world, people have reported sexual contact with various supernatural creatures. Many people believe that “sex demons” were born out of the need to explain topics that are generally considered taboo. Usually, unintended pregnancy, miscarriage and promiscuity can cause anger and persecution.
A mare (also mara or mora) or nightmare is an evil spirit or goblin in Germanic folklore which rides on people’s chests while they sleep, bringing on bad dreams (or “nightmares”). The mara is attested as early as in the Norse Ynglinga saga from the 13th century, but the belief itself is likely to be considerably older. The mara is often similar to the mythical creatures succubus and incubus and was likely inspired by sleep paralysis.
The mara was also believed to “ride” horses, which left them exhausted and covered in sweat by the morning. She could also entangle the hair of the sleeping man or beast, resulting in “marelocks,” called marflätor (mare-braids) or martovor (mare-tangles) in Swedish. The belief probably originated as an explanation for the Polish plait phenomenon, a hair disease.
According to the author and researcher Paul Devereux, mara included witches who took on the form of animals when their spirits went out while they were in a trance. Animals such as frogs, cats, horses, hares, dogs, oxen, birds, and often bees and wasps. Like other trance practitioners, mara witches traditionally owed their abilities to being born with a caul. Dead mara witches were said to return as ghosts.