Wikipedia
Bergsrå
The bergsrå , (Mountain Rå), Bergatrollet (Mountain Troll) or Bergakungen (Mountain King), was a mythical creature of the mountain, or Rå, in norse mythology.
The bergrå could be either male or female. It lived in the mountain with a court of relatives and sometimes surrounded by trolls. It was a common phenomena in the mythology about the bergsrå for humans to be bergtagen (literary: "taken into the mountain"), spend time with the bergså in the mountain. A typical description of such a claimed occurrence was given by Sven Andersson in 1691, when he was on trial for having sexual intercourse with a female bergrå.