Anime: Ponyo on the Cliff by the Sea
Heavily inspired by The Little Mermaid, particularly the original Hans Christian Andersen version, Brunhilde is a fish that can transform into a human.
She’s mischievous, given her infantile age, and quickly bonds with Sosuke: a human she becomes attached to.
Her design is simple in both forms, and she manages to look but human and fishlike no matter what!
10/10