The swan maidens were Welsh fees who could transform themselves into swans by wearing a cloak of feathers.
It was said that if this cloak was acquired by a mortal, he could command them and force them to remain in human form. Many marriages resulted from men stealing the magical garments of the swan maidens, in much the same way as one could command a selkie (one of the seal folk of Scottish and Irish legend) if one gained her skin.
- The swan maiden has appeared in numerous items of fiction, starting with the ballet Swan Lake and continuing in modern novels of the fantasy genre such as Three Hearts and Three Lions and television such as Astroboy Episode 5.
- A notable recent appearance is of the swan-men in the Anita Blake series, including Kaspar Gunderson.
- They are also called swan mays or swanmays in fantasy fiction and Dungeons and Dragons.
- A series of animated movies were created under the title The Swan Princess, in which a young princess is cursed by a sorcerer and turns into a swan. By night she transforms back into her human self, and is eventually rescued by a prince.
- In the Mercedes Lackey book, Fortune's Fool, one swan maiden (named Yulya) from a flock of six is kidnapped by a Jinn.