The Nixie, Nixy,[1] Nix,[1] Näcken, Nicor, Nøkk, or Nøkken (German: Nixe; Dutch: nikker, nekker; Danish: nøkke; Norwegian Bokmål: nøkk; Nynorsk: nykk; Swedish: näck; Faroese: nykur; Finnish: näkki; Icelandic: nykur; Estonian: näkk; Old English: nicor; English: neck or nicker) are humanoid, and often shapeshifting water spirits in Germanic mythology and folklore.
Under a variety of names, they are common to the stories of all Germanic peoples,[2] although they are perhaps best known from Scandinavian folklore. The related English knucker was generally depicted as a worm 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.[2] Similar creatures are known from other parts of Europe, such as the Melusine in France, the Xana in Asturias (Spain), and the Slavic water spirits (e.g., the Rusalka) in Slavic countries.