Mine goes waaaaay back... back when I was into snowcross and motocross. XC for the sled, and YZ for the bike. I've been using this name for as long as I've been on the internet.
Calvin & Hobbes a comic strip written and illustrated by Bill Watterson is my all time favorite. Calvin went on many adventures as different characters, one being Space Man Spiff...my favorite of the lot. Being a pilot I had AV8 on my license plate a few years back and it just kind of stuck. Combine the two and you've got it. It was that or Lucky13.
__________________ Curtis
Pilots: We're not better than you, just way cooler.
I used to have a tricked out late model mustang that I converted into a Cobra mustang. A magazine editor coined it a "fakesnake" and the name stuck plus I set up a web page for my cars and later added the .com. Just a hobby (expensive one).