A famous Japanese yōkai, the Kappa is a mischievous aquatic creature—humanoid in shape, green-skinned, web-footed, and sporting a turtle-like shell with a bowl (“sara”) on its head that must remain filled with water to retain its power. Kappa-Dera, officially Sogenji Temple in Tokyo’s Kappabashi district, is the temple most closely associated with the legend; it claims that Kappa once helped drain floodwaters for locals, the temple even preserves a mummified Kappa hand.