The “Real” Tanuki
The tanuki is considered a member of the canine family, it is usually mistaken for a raccoon. It is a native species of Japan and Manchuria but they can also be found in many places in Asia until eastern Europe.
Here’s a photo of a tanuki that I took in 2005 when I had just arrived to Japan; by that time I had no idea what it was, at the beginning I was a little bit scared but I soon realized that it is a quite calm creature and that I could easily take pictures of it.
The Tanuki Myth
Japanese folklore has thousands of references about the tanuki. According to mythology tanuki are able to transform into any form.
Nowadays at the entrance of many Japanese restaurants you can find a tanuki statue. On the left hand the tanuki usually holds a sake bottle, its favorite drink, and on the right hand an accounting notebook. Legend has it that tanuki bring good fortune and healthy profits.
Another characteristic of tanuki statues is the size of their testicles. Notice them in the picture, as the base of the statue are not the feet, but Kin-tama (literally golden eggs). The huge testicles are a symbol of good luck and many tanuki tales portray tanuki using their testicles as drums or even their scrotum skin as a parachute. The use of the “golden eggs” as drums can be seen in Ghibli’s movie Pom Poko. This could be a good example of Japanese humor.
Super Mario Tanuki
It turns out that the raccoon suit in Super Mario Bros. 3 is in fact a tanuki suit that gives him superpowers frequently associated to tanuki in Japanese mythology. When Mario is wearing the tanuki suit he can turn into an invincible statue.
More info in Wikipedia.