Melusine
Melusine or Melusina is a figure in European folklore and mythology (Celtic, Brittany). A female spirit of fresh water in a sacred spring or river. She is usually depicted as a woman who is a serpent or fish from the waist down (much like a mermaid). In some cases she is depicted as having two tails instead of one, and also is said to have wings. Melusine was a water fairy who married a mortal.