A user called current93, named after a band; numerous pics of japanese anime; names of mythological gods/beasts, biblical angels, or variations thereof; or first initials with last names; various vampire terms (a user named lamia); and on and on.
When I originally created my name, Aryx, it was the respelling of my first name combined with the initial of my last name. But I was a teenager at the time, when there were 5 guys with the same name in the same class! I later found out that it is a real name, named more often to girls than boys, but androgynous. I think it means something like, "from the dark side," or something like that. I also found that someone beat me to registering it as a dot com. :-( BUT! One interesting side note: Aryx is an anagram of what I do for a living. That is, if you rearrange the letters of aryx, you come up with a new word, which states what I do. For those of you who are mentally challenged, the answer is x-ray.