The Huldra myth

A Hulder is a forest creature found in Scandinavian folklore; in Norwegian folklore, she is known as the Huldra. She is known as the skogsrå or Tallemaja in Swedish folklore, and Ulda in Sámi folklore. These fair-haired blonde beauties are often said to lure men into the woods by their lovely singing, appearance or hypnotic harp playing to do their bidding. The Hulder if betrayed are known to punish their victims severely. They help and punish, set limits, make trouble for people or generously endow valuable gifts; the way a Hulder reacts to you is based on how you treat her. Treat her with respect and she may reward you, treat her cruelly and receive the same. The moral of this story is treat others how you want to be treated.

Appearance: A beautiful and seductive woman having a hollow, bark-encrusted back and/or an animal tail.

Lore: Like the Greek nymphs of lore, Huldra have overactive sex drives and will seduce and lure men into the forest in order to have sex. If the man can satisfy her needs, she lets him live and even blesses him with her power. However, if the man cannot satisfy her sexually then she will usually kill him. Even if a man can sexually satisfy a Huldra it doesn't imply his safety, for it is believed that he will be unable to resist her advances and will literally exhaust himself to death via repeated couplings.

Like fairies, Huldra will abduct human children and leave behind a changeling, one of her own children in it's place. Also like fairies, Huldra can and often do marry mortal men. When such a situation arises, the Huldra will extract a promise from her mortal husband. 

However, if a man did marry her (in a church in the name of god), tales tell that she would turn into an ugly woman. But in return she would gain the strength of ten men if not more, and she would lose her tail.

Despite their dangerous side, Huldra do have a beneficial role. Huldra do offer assistance, usually in the capacity of keen observers and warning of anything that might go wrong. In return for their service, Huldra are offered food and drink.

As to the origin of the Huldra, according to legend the Huldra originated when God visited a woman with a great number of children. The woman had only bathed a certain portion of her children and only presented the clean children to God when he asked to see them. The woman hid her dirty children from God. God became so angry at her trick that he cursed her saying from then on her dirty children should continue to be hidden from mankind, ultimately giving rise to the Hulderfolk.

One of the quickest ways to arouse the wrath of a Huldra is to make fun of, or be rude concerning, her tail. Be warned.

Powers: Fairy glamour, power to cause insanity, incredible strength, and the power to grant bountiful catches in fishing and hunting.

Defense Against Huldra: Being similar to fairies, Huldra might fear iron objects and salt. Huldra women who marry men will lose their powers of fairy glamour when blessed by a priest. According to folktales it is possible to outwit Huldra.