|Purpose||To stop children wandering|
Kappa 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. Kappa 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. The expression kappa-no-kawa-nagare ("a kappa drowning in a river") conveys the idea that even experts make mistakes. Although their appearance varies from region to region, the most consistent features are a carapace, a beak for a mouth, and a plate (sara), which is a flat hairless region on top of their head that is always wet, and which is regarded as the source of their power. This cavity must be full whenever a kappa is away from the water; if ever dries, the kappa will lose its power, and may even die, according to some legends. Another notable feature in some stories, is that the kappa's arms are said to be connected to each other through the torso and able to slide from one side to the other.
Kappa are usually seen as mischievous troublemakers or trickster figures. Their pranks range from the relatively innocent, such as loudly passing gas or looking up women's kimonos, to the malevolent, such as drowning people and animals, kidnapping children, and raping women.
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 drinking their blood, eating their livers or gaining power by taking their shirikodama (尻子玉?), a mythical ball said to contain their soul which is located inside the anus. Even today, signs warning about kappa appear by bodies of water in some Japanese towns and villages. Kappa are also said to victimize animals, especially horses and cows; the motif of the kappa trying to drown horses is found all over Japan. In these stories, if a kappa is caught in the act, it can be made to apologize, sometimes in writing. This usually takes place in the stable where the kappa attempted to attack the horse, which is considered the place where the kappa is most vulnerable.
While they are primarily water creatures, they do on occasion venture on to land. When they do, the plate can be covered with a metal cap for protection. In fact, in some incarnations, kappa will spend spring and summer in the water, and the rest of the year in the mountains as a Yama-no-Kami (山の神, “mountain deity”). Although they are reported to inhabit all of Japan, they are often said to be particular to Saga Prefecture.