Gangi Kozō

The Gangi Kozō is a yokai from Japanese mythology. They are described as monkey-like creatures covered in hair with hair on their heads in a style called Okappa, which was once common with children. They have webbed hands and thin sharp teeth similar to files. They are thought to be related to the Kappa, and some even believe that Kappa transition into mountains spirits when the seasons change, and the Gangi Kozō is the intermediary between these two forms. They live on riverbanks and eat fish. When fishermen encounter these creatures, they are supposed to leave their largest and cheapest fish as an offering.

Citations:

Meyer, Matthew. The Book of the Hakutaku: A Bestiary of Japanese Monsters. United States, Matthew Meyer, 2019.