Here you go:
"Kappa are Japanese sprites in Japanese folklore, often depicted as tortoise-like humanoids with green skin, beaked faces, and shells on their backs. A cavity on the top of their heads is filled with water and is said to be their vulnerable spot - when it's dry, they lose their energy and power. Kappa appear in a lot of Japanese comics, animation, TV commercials, etc. They are loved by people as a cute character despite the fact that they are rumored to drag humans into the water and pull out their guts through their" (guess)