Many monsters of myth and legend exist to explain natural phenomena. The terror that comes from being half-awake and unable to move was personified by many cultures, especially when the fears of night persisted into the day. The creature that was held responsible is referred to in English as the Night Hag, but also goes by the name of the Old Hag and the Mare – the creature from whom the term ‘nightmare’ gets its name.
One of the most intriguing parts of the Night Hag mythology is that the creature doesn’t seem to have a single visual cue that would separate it from other similar folkloric creatures. Night Hags are almost always described as monstrous, but they can take the form of anything from a small, imp-like creature to a more proper demon. What’s important is that they are rarely described as being larger than the humans on which they prey.
It should be noted that some European mythologies class this creature as a relative of the incubus, which would likely put its physical shape as something approaching human or demonic. In other cultures, though, the descriptors tend to be more animalistic – both dogs and mice are considered suitable points of comparison in some Asian versions of the myth.
Night Hags tend to have the power to cause what science now refers to as Sleep Paralysis. In this state, an individual is at least semi-conscious but is unable to move. Many individuals who experience sleep paralysis tend to report high levels of fear and some also experience hallucinations.
In folklore, Night Hags can also have a tendency to cause other issues that might be related to sleep paralysis. Night Hags are sometimes considered to steal the breath of their victims, which would line up with the difficulty in breathing some encounter during sleep paralysis. In other cases, though, Night Hags might be reported to steal the life-force of their victims.
The Night Hag is, perhaps more than most other creatures, an entity that is more based in general folk tales than in any codified myths. While the Night Hag’s name is generally related to the phenomenon in English-speaking countries, it actually shares its roots with similar creatures that can be found across the world. The Night Hag is, in many ways, the root explanation for both the phenomenon of sleep paralysis as well as the basis for the modern idea of the nightmare.
Generally speaking, the creature’s stories play out the same way no matter what name it goes by or in what culture it exists. The Night Hag sits upon its prey at night, making it impossible for the victim to move. In some cases, the Night Hag is the source of horrible nightmares. In other cases, the Night Hag drains the victim of energy or might even be the cause of the individual’s death. What is important is that the Night Hag always comes when the victim would otherwise be asleep and that it always leads to some kind of negative result for the sleeper.
Interestingly, few Night Hag stories talk about any kind of protection from the creature. The Turkish iteration can be banished by prayer and reading the Qu’ran and the Maltan version can be banished by hiding silver under one’s pillow, but most cultures seem to view the Night Hag as a creature that must ultimately be suffered if it comes in contact with a person.