What is it with multiple tails on dogs/wolves?

[Redcoffin]

A lot of anime depict dogs, foxes or wolves with more than one tail. Examples include from Princess Mononoke, Inu Yasha and others, and of course Sonic the Hedgehog's pal Tails. Is this double-tailed thing a feature from Japanese folklore? I never heard of it outside of anime.

[yuzuha]

I think the 9 tailed fox originated in India but generally multiple tails means a supernatural creature like the bakeneko in Inu Yasha.
We did a thread on Japanese ghosts and demons on AN japanese demon thread (http://www.animenation.net/forums/showthread.php?t=162650)