In Japanese folklore, “kappa” are bipedal, turtle-like aquatic goblins who sometimes grab unsuspecting humans, often children, as they walk over bridges or through swamps, pulling them down into the muck to drown them.
The fishy-smelling kappa’s most distinct feature is the bowl-like dent on the top of its head, which it must keep filled with water at all times to stay alive.
The Tokyo neighborhood of Kappabashi (literally “Kappa’s Bridge”) was supposedly so plagued by the creatures that its inhabitants built a small kappa-temple to appease them.
The temple, called Sougenji or Kappa-dera, still stands today. Its altar is kept piled high with offerings of cucumbers - said to be the kappa’s favorite food - and its treasure chamber contains antique scroll-drawings of the goblins and even a “real” dried and preserved kappa-arm.
Visitors should keep an eye out for the numerous statues of kappa that stand outside local shops. Some of these are cute and cuddly, but others are decidedly creepy.
Anyone encountering a real kappa should remember to stay calm and, most of all, to be polite: Bowing to a kappa will oblige the kappa to bow in return, emptying its head-bowl of life-sustaining water and sending it back to the spirit realms.