Kappa - legendary creature -

Kappa is one the most familiar mythcal creature in Japan. They are child-sized humanoids and look like frog. The most distinctive feature is that they have "dish" on their head and turtle's shell on their back. They inhabit rivers and are sometimes mischievous like kidnapping children into river. I think they used to play a roll to warn children to swim river without adults supervision.

Kappa are not entirely antagonistic to mankind, however. They are curious of human civilization, and they can understand and speak Japanese. They may even befriend human beings in exchange for gifts and invite children to play Sumo with. Because Kappa likes cucumber, the sushi rolling up cucumber are called "Kappa roll".

"Kappa roll"