Neck (water spirit) vs Nereid

Neck (water spirit)
The neck, nicor, nokk, nix, nixie, nixy, or nokken (German: Nixe; Dutch: nikker, nekker; Danish: nøkke; Norwegian Bokmål: nøkk; Nynorsk: nykk; Swedish: näck; Faroese: nykur; Finnish: näkki; Estonian: näkk; Old English: nicor) 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.
Statistics for this Xoptio

Nereid
In Greek mythology, the Nereids ( NEER-ee-idz; Greek: Νηρηΐδες Nereides, sg. Νηρηΐς Nereis) are sea nymphs (female spirits of sea waters), the 50 daughters of Nereus and Doris, sisters to their brother Nerites. They often accompany Poseidon, the god of the sea, and can be friendly and helpful to sailors (such as the Argonauts in their search for the Golden Fleece).