In Japanese folklore, the water imp known for pulling children and other victims into rivers is the kappa.
The kappa is a water-dwelling yōkai associated with Japan’s rivers and ponds. Older stories portray it as dangerous, dragging people, horses, and cattle into the water and drowning them. Later folklore often softened the creature into a mischievous being that could be tricked, captured, or persuaded to help humans.
Traditional descriptions combine human, turtle, and sometimes amphibian features: a small body, webbed hands and feet, a turtle-like shell, and a dish-shaped depression on the head. This dish holds water, which is said to provide the kappa’s strength. Bowing can therefore be a successful defense, because the kappa may bow back and spill the water.
Kappas are famously fond of cucumbers and sumo wrestling. Their legends vary widely by region, and they have at least dozens of local names. Some communities treated them not merely as monsters but as dangerous or helpful water spirits connected with suijin, the Japanese tradition of water deities. They are not the same as kitsune, oni, or tengu.