great website! You know, if we hadn't already determined it to be Fluffy, both the ringtail and the spotted skunk are found in NorCal and they both carry their tails low enough to often obscure their tracks. And they are very small, not much bigger than fluffy, so they could hide in that same spot. Spotted skunks can fit through almost any sized hole there is - I had one in a cat carrier once, one of those cardboard ones with the small row of holes at the top? and it got out, in my car. I had to create a special carrier (we call it the Fort Knox carrier) to transport it anywhere, it looks like something you would put Hannibal Lecter in. (if he were very very small and stinky)
I would be very envious if you had either one of them. I have only ever seen them in the wild once, each.