Tanuki have been part of Japanese myth since ancient times. The mythical tanuki is reputed to be mischievous and jolly, a master of disguise and shapeshifting, but somewhat gullible and absent-minded.
WARNING: TANUKI PORN BELOW(Don't say I didn't warn you)
The current humorous image of tanuki is thought to have been developed during the Kamakura era. The wild tanuki has unusually large testicles, a feature often comically exaggerated in artistic depictions of tanuki. Tanuki may be shown with their testicles flung over their backs like a traveller's pack, or using them as drums. Tanuki are also typically depicted as having large bellies. They may be shown drumming on their bellies instead of their testicles, especially in children's art.
Here are several portrayals...
Kind of makes sense. Chimps - a highly promiscuous species - have large testicles due to among other things sperm competion between males. Since tanukis live in groups, one wonders if the same competition between male sperm might happen...?
This does not exhaust the list of remarkable things about the tanuke though. For you see the tanuki have theological implications as well. From Wikipedia:
Statues of tanuki can be found outside many Japanese temples and restaurants, especially noodle shops. These statues often wear a big, cone-shaped hat and carry a bottle of sake. Tanuki statues always have a large belly, although contemporary sculptures may or may not show the traditional large testicles. These exaggerated features represent fertility and plenty.
Note the bolded words "...especially noodle shops." Which, of course, implies some kind of relationship between the Flying Spaghetti Monster and tanuki. If you think about it the relationship becomes really clear. Pastafarians belive there is a beer volcanoe in heaven. What happens when you drink lot's of beer for long periods of time? You get a beer belly just like the tanuki. Pastafarians also belive there is a stripper factory in heaven, which leads us to the other prominent characteristic of tanukis...