Hulder (Huldra)
Hulder (also called Huldra) is a supernatural female forest spirit in Norwegian folklore. Part of the huldrefolk (hidden people), she is known for her breathtaking beauty and seductive nature. She appears as a tall, fair young woman with long golden hair, but has a hollow back like a rotten tree trunk and a cow's tail that she tries to hide. The hulder lures men into the forest with her enchanting voice and dancing, often seducing them. If a man refuses her, she may kill him or he goes mad (becomes huldrin - bewitched). She can reward kindness, especially to charcoal burners whom she protects.