Sushi fans will probably know that cucumber rolls are known as kappamaki in Japanese. This is in honor of what is surely one of Japan's strangest mythical creatures — the kappa.

Although reptilian in appearance with webbed hands and feet, and shells on their backs, kappa can walk on two legs and use their bird-like beaks to communicate with humans.

The creatures are sometimes called "water sprites" in English, but possess some rather unpleasant characteristics that are more in line with the carnivorous troll under the bridge in the Norwegian fairy tale "Three Billy Goats Gruff."