The Tanuki (or Japanese Raccoon Dog) is a basal canid, or primitive member of the canine family, related to dogs and foxes but in its' own separate subgroup. As the name suggests, they are native to Japan and other areas of Asia. In older English translations from the Japanese they are sometimes referred to as badgers, or more recently, raccoons, but they are neither.
In Japanese folklore they are seen as supernatural creatures, not unlike the kitsune, or fox spirits, but are perceived as more bumbling and good-natured. They are supposed to have powers of transformation, activated when they put a leaf on their heads; this is referenced in the video-game Super Mario Brothers 3.
The most outstanding features of tanuki males, in both real life and in popular culture, are their large testicles. These are seen as signs of good fortune and abundance. The supernatural tanuki are said to inflate them and beat them like a drum to scare off enemies.