Kappa

Kappa (河童), legendary creatures, a type of water sprite found in Japanese folklore. As water monsters, kappa have been frequently blamed for drownings, and are often said to try to lure people to the water and pull them in with their great skill at wrestling. They are sometimes said to take their victims for the purpose of eating their livers. Kappa are not entirely antagonistic to humankind, however. They are curious of human civilization, and they can understand and speak Japanese. 

  Kappas are typically depicted as roughly humanoid in form, and about the size of a child. Their scaly, reptilian skin ranges in color from green to yellow or blue. Kappas supposedly inhabit the ponds and rivers of Japan and have various features to aid them in this environment, such as webbed hands and feet.They are sometimes said to smell like fish, and they can certainly swim like them. 

It was believed that if confronted with a kappa there was but one mean of escape: kappas, for one reason or another, obsess over being polite, so if you were to gesture a deep bow to a kappa it would more than likely return it. In doing so, the water kept in the lily-pad-like bowl on their head would spill out and the kappa would be rendered unable to leave the bowed position until the bowl was refilled with water from the river in which it lived. If a human were to refill it, it was believed the kappa would serve them for all eternity