Kappas are a fictional sapient species featured in Harry Potter.
Description[]
Kappas are a species of magical scale-covered monkeys from Japan, who possess magically-increased strength, the focus of which is the water they keep in a depression in their skull. Kappas are sentient but hostile, as they feed on blood, including that of humans they strangle and pull into the ponds they inhabit. They can be greatly weakened if they can be forced to bow, so as to empty the water in their skull.