Thanks to Gene (and others) for the information on the critter in my garden. He said:
"I suspect you saw a Virginia Opossum (_Didelphis virginiana_) a.k.a opossum. Like rats they have a scaled tail. A rat-sized individual is most likely a young animal. Adults can reach 8 -15 inches & weigh 4-10 lbs. They are primarily nocturnal & are scavengers. It's the only native marsupial in North America.
They are nearsighted, have poor hearing & in the face of danger tend to pretend to be dead, hence the phrase "playing 'possum.""
Good to know, huh? I have to admit, I had an initial shiver run through me when I first saw it and thought it might be a huge rat -- it's sorta too bad that we have these instinctive reactions. At least I like spiders (a good thing, because my house is apparently a spider haven. We even considered naming it Spider's Rest, but Cliff said that was a bad idea, 'cause it would call more spiders, given the power of names. Then we starting tossing around other names -- I think our favorite was Spiders Stay Out of Bedroom House -- 'cause while we're all kind of fond of spiders, none of us likes the ideas of spiders accidentally dropping into our faces in the middle of the night...(okay, this is really silly. I'd ask you all for naming suggestions for our house, except you haven't seen the place, and you don't know my roommates, so I doubt you could really help much...)). Anyway, the opossum was actually pretty cute once I got a good luck at it.
Anyway, back to work. Talk to y'all later...