Kappa (河童) is a creepy child-like, frog-like creature that has a bowl of water in its head. They also have a shell and a beak and webbed fingers and toes. They’re very mischievous and they’re excellent swimmers becuase they live in the rivers and lakes. They always have to have water in their bowl though, because the water gives them strength. It’s like their blood.
They like playing pranks on people, and sometimes they do worse things too, like drowning people. But if you can somehow get it to spill the water on its head by making it bow down to you or otherwise, you can make the kappa subservient to you.
They love eating cucumbers. Some people say that if you eat cucumbers before you go swimming, you’ll get attacked by a kappa, but others say it could prevent that from happening.
Informant had studied abroad in Japan and considers herself more Japanese than Chinese or American. She learned such folklore from her Japanese friends. The story of the kappa may be used as a cautionary tale in Japan to keep children from playing in water without supervision.