Hulder

A hulder (also spelled huldra) is a female creature from Scandinavian folklore, often depicted as a beautiful woman with long hair and a cow's tail.

She is said to live in the forest and lure unsuspecting men into danger with her enchanting voice and beauty. Some legends describe her as a shape-shifter who can transform into a bird or animal, while others suggest that she is a guardian of nature who punishes those who harm the forest.