srondlurk
Mythical being originating from Scandinavian folklore. A hideously ugly creature that was believed to cower in dark corners of rooms. Usually they are portrayed as only being able to exist in darkness or very dim light. They are observers; they do not meddle in human affairs and prefer to remain in secret, watching. But should they be discovered, or worse, confronted, then it was believed they would effectively become bound to their discoverer's soul, tormenting them in their sleep with terrifying nightmares. This was said to be only a glimpse into the horrors that would await the afflicted in the afterlife. Hence the old Finnish saying: "Look ye not to the darkness, lest ye be forever bound to the srondlurk". Often described as being of the size of a child, dark yet reflective eyes, flesh of charcoal, gray, or pasty white color, thick black hair ("made of shadow" in some accounts), it is usually portrayed as a creature whose existence should be accepted but generally ignored (the "let sleeping beasts lie" folk motif). Many folklorists consider the srondlurk to share a common history, or perhaps even be the origin of the boogeyman.
"May you sleep with the srondlurk this night!" (A common curse, uttered, for example, after a bar fight)