* Japanese name: Kappa
* Scientific name:Suijin kappensis
* Description: Some sources claim that kappa are primates, but in fact they are the only known examples of an order of primitive mammals related to the duck-billed platypus. Remarkably for a mammal, kappas are bipedal. They have a curved duck's beak, as well as webbed hands and feet, yellow-green scaly skin, and a hard shell-like casing on their back. The scales and the shell are secondarily derived from fur (one of the defining characteristics of mammals). The top of the skull, uniquely, has a cavity which is filled with water.
* Where to find them: As can be deduced from their adaptations to aquatic life, kappa live in and around rivers. They are endemic to Japan and can be found on all the islands, except Hokkaido, where it is too cold. Like other animals reliant on water, their populations have been badly affected by environmental degradation. Interestingly, encounters with kappa are most often reported after large amounts of alcohol have been consumed.
* Food:Kappa have been rumored for centuries to eat horses, cattle and even children, but whatever their ancestral diet, kappa these days are vegetarian. They are particularly fond of cucumber, and the sushi roll filled with cucumber, kappamaki, is named in their honor. As important to a kappa as food, however, is water. Their brain activity can be so intense that a coolant system is needed to stop the animal overheating. To this end, the kappa has evolved a cavity in its skull which the animal must keep filled with water. If the water is spilled from the cavity, the animal's head overheats and it becomes extremely weak.
* Special features:The bursts of brain activity can be greater than humans, hence the need for a coolant. But no one knows what kappa are thinking at the moments of intense brain activity. In times past, the kappa was thought to be mischievous, dangerous and even evil. In Japanese folklore, kappa represented the outsider. But as Japan has modernized, so the kappa has adapted to the new thinking. As outsiders are no longer feared and reviled as much as before, so the kappa is becoming at worst a benign presence, at best friendly and lovable.