|“||River demons from Japanese folklore. They appears as a cross between a snapping turtle and a monkey, and are known for drowning people and raping women. Despite this, they are considered one of Japan's most popular youkai and have appeared in countless children shows.||„|
|— Carl Black.|
It is typically depicted as roughly humanoid in form and about the size of a child. Kappa are usually seen as mischievous troublemakers or trickster figures. Their pranks range from the relatively innocent, such as looking up women's kimonos, to the malevolent, such as drowning people and animals, kidnapping children, and raping women. A kappa's appearance is that of scaly reptilian skin that 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 swim like them.
As water monsters, kappa have been blamed for drownings, and are often said to try to lure people into 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, a mythical ball said to contain the soul.
Although their appearance varies from region to region, the most consistent features are a beak, a shell, and a plate (sara), a flat hairless region on the top of the head that is always wet, and is regarded as the source of the kappa's power. This cavity must be full whenever a kappa is away from the water; if it ever dries out, the kappa loses its power and may even die.
It was believed that, if one was confronted with a kappa, there were a few means of escape. Kappa are obsessed with politeness, so if a person makes a deep bow, it will return the gesture, the water in the plate on its head spills out and it is rendered unable to leave the bowing position until the plate is refilled with water from the river in which it lives. If a person refills it, the kappa will serve that person for all eternity. A similar weakness of the kappa involves its arms, which can easily be pulled from its body. If an arm is detached, the kappa will perform favors or share knowledge in exchange for its return. Another method of defeat involves shogi or sumo wrestling: a kappa sometimes challenges a human being to wrestle or engage in other tests of skill