One peculiar trait is that it has a cavity on its head called a "sara" ("dish", "bowl", or "plate") that retains water or some sort of liquid, which is regarded as the source of the "kappa"'s power or life force. This cavity must be full whenever a "kappa" is away from the water; if it ever dries out, or if its water is spilled, "kappa" loses its power and may even die. The "kappa" are sometimes said to smell like fish, and they can swim like them.