Up for a little dip in the pool? What about down by the river? Look out! The Nixies might grab you!
The neck, nicor, nix, nixie, nixy, or nokken (German: Nixe; Dutch: nikker, nekker; Danish: nøkke; Norwegian: nøkken; Swedish: näck; Finnish: näkki; Estonian: näkk) are shapeshifting water spirits in Germanic mythology and folklore who usually appeared in the form of other creatures.
Under a variety of names, they were common to the stories of all Germanic peoples, although they are perhaps best known from Scandinavian folklore. The related English knucker was generally depicted as a wyrm or dragon, although more recent versions depict the spirits in other forms. Their sex, bynames, and various transformations vary geographically. The German Nix and his Scandinavian counterparts were male. The German Nixe was a female river mermaid.
The German Nix and Nixe (and Nixie) are types of river merman and mermaid who may lure men to drown, like the Scandinavian type, akin to the Celtic Melusine and similar to the Greek Siren. The German epic Nibelungenlied mentions the Nix in connection with the Danube, as early as 1180 to 1210.
Nixes in folklore became water sprites who try to lure people into the water. The males can assume many different shapes, including that of a human, fish, and snake. The females bear the tail of a fish. When they are in human forms, they can be recognised by the wet hem of their clothes. The Nixes are portrayed as malicious in some stories but harmless and friendly in others.
By the 19th century Jacob Grimm mentions the Nixie to be among the “water-sprites” who love music, song and dancing, and says “Like the sirens, the Nixie by her song draws listening youth to herself, and then into the deep.” According to Grimm, they can appear human but have the barest hint of animal features: the nix had “a slit ear”, and the Nixie “a wet skirt”. Grimm thinks these could symbolise they are “higher beings” who could shapeshift to animal form.
Read more from Wikipedia here.