Nachtmerries

The Nachtmerrie, Nachtmare or Mare (translation: Nightmare) is a type of witch, closely related to the werewolves. The Nightmare could change into any size she wanted, so she could sneak into any house. At night she would tread out of her body and become a translucent vampire, oftentimes riding an insect towards her destination. By riding living creatures, she depleted their energy. Her targets were oftentimes humans, but also horses were a favorite. Sometimes (probably as a last resort) she would ride trees. Whatever the Nightmare rode would get entangled, causing bad hair, wild manes or even twisted branches. Horses ridden by the Nightmare were found drenched in sweat the following morning. Sometimes they would not survive the ride. Nightmare have been known to either be really old and ugly; causing bad dreams, or extremely good looking; which causes wet dreams. They have never shown up as an average-looking person, although they have been known to show up as a cat or similar-looking furry creature. Derived from the Indo-European "Mer," Mare means "evil". Some believed the Nightmares were part of the Elven community, as the Elves have been known to fool people with their illusions. Whenever a Nightmare targets human beings, she would sit on their chest to ride them like a horse. Those she rid, claimed they could barely get any air.

Becoming a Mare
Only women can be nightmares. The most beautiful of 7 daughters is said to be contacted by the devil, who would then offer her Nightmare abilities. Similarly, the devil offers one of 7 sons the ability to transform himself into a werewolf. It is understood that both Nightmares and Werewolves are eachother's counterparts and live to serve the devil.

Roots to Lilith
According to Hebrew texts, Lilith was Adam's first wive, made from dirt, just like Adam was. When it came to intercourse though, Adam did not allow Lilith to be on top during sex. The couple clashed, so Lilith left Adam. God then made Eve from Adam's rib, so that she might be more submissive to Adam. What followed is speculation. Lilith swore revenge against those destined to populate the earth. Some say she turned to the devil, had sex with him and spawned a race of vampires. Alternatively, she visited Adam in spirit, causing wet dreams. Adam's seed then gave birth to the vampire race. Among the vampires was a subspecies known as the succubus; a deadlier version of the nightmare.

Repelling Nightmares
People were scared of Nightmares, so of course they did all they could to keep them out. There were several methods. Perhaps the most well known method was hanging a sieve or fishnet above the bed. The Nightmare would then proceed to enter each hole before getting to her target. Instead, she got stuck in an endless loop. Other methods involved specific placement of footwear. Iron, maretakken (translation: Mistletoes) and incantations have also been known to drive off Nightmares. Farmers were known to hang mounted horse heads above the barndoor, to keep Nightmares from riding their horses.