Piscine and amphibian humanoids (people with the characteristics of fish or amphibians) have made appearances throughout mythology, cryptozoology, folklore and fiction.
, a piscine humanoid reported in Poland in the 16th century
- Dagon in Semitic mythology
- Huh: Ancient Egyptian frog-headed god whose name means "endlessness".
- The each uisge or "water horse" from Scottish folklore, could assume the form of a man
- Sirens, while initially described as birdlike, were associated with mermaids in later folklore
- The Fishmen are a race of fish-like humans from the anime One Piece.
- The Frogman, a character from the Oz novel series