Kappa (folklore)

In traditional Japanese folklore a kappa (河童; "river-child")—also known as kawatarō (川太郎; "river-boy"), komahiki (駒引; "horse-puller"), with a boss called kawatora/senko (川虎; "river-tiger") or suiko (水虎; "water-tiger")—is a reptiloid kami with similarities to yōkai. Kappa can become harmful when not respected as gods. Accounts typically depict them as green, human-like beings with webbed hands and feet and turtle-like carapaces on their backs. A depression on the head, called a "dish" (sara), retains water, and if this is damaged or its liquid is lost (either through spilling or drying up), a kappa becomes severely weakened.

The kappa favor cucumbers and love to engage in sumo-wrestling. They are often accused of assaulting humans in water and removing a mythical organ called the shirikodama from their victim's anus.