Mine - I’m a mom and I like Spongebob.
I’ve seen some very interesting usernames on here, and I’m bursting with curiosity as to how they were chosen. 
I’m a raccoon.
Really…
Way back when I started playing online I needed a mud name. All the “good ones” were taken. I needed an idea. The book for SuperMario2 was on my desk and it had all the names of his suits. The tanookie suit is the name for the raccoon suit. I’ve been using the name now for 13ish years… I’m always peeved when I go to sign up for something and find my name taken!
Y’see, I would’ve guess that you’re a mom because the sponge failed you.
Mine is easy. I like “The Tick” and American Maid is the only recurring female hero.
As you can easily see, I went braindead as soon as the signup form was in front of me. (Paper forms work the same way. I can usually get through my name and address with no problem, but my pulse starts to race as I’m filling in my phone number and I go on from there.) I went with my initials so the damn form would just go away.
I adopted the name of the elderly Turtle Wizard in Alan Dean Foster’s Spellsinger novel series.
1.) It’s sounds badass.
2.) It sounds like the name of nordic warrior; I am pround of my sweedish and danish heretige.
3.) Its my nickname amoung friends.
4.) Its my name on most video games/web forums.
Time for some copy & paste action from the last time I posted to one of these back in April:
Well, since Ted Striker was taken, I had to extend it to Theodore. Of course, if you don’t know who Ted Striker is, then this means nothing to you, and you need to go rent the Airplane movies.
And to AmericanMaid… SPOON!
It’s very simple where my name came from
A great love for Iggy Pop + A great love for vodka=
iggy popov
I needed a username. There was a stack of CD’s next to me. The rest is history.
I like to read and learn about first century Ancient Rome, and I like the name “Agrippina”. More info found here.
I originally only had the user name as a character on Kingdom of Loathing. But I got to thinking about it and really liked it as a user name and had my name here changed several months ago (I used to be Rabid Child—a name I got from a They Might Be Giants song).
Oddly enough, it’s the first user name I’ve had since joining the Internet seven years ago that I’m finally happy with.
Back when I first signed onto some messanging system or other in maybe 1994 or 95, Gandalf, Frodo, Turin, Ancalagon, etc etc (though I admit I didn’t check for Fatty Bolger) were already taken, and there was no way I was going to have a silly number in my user name (no offense to those who do). So, out came the Tolkien encyclopedia and I finally found a name I liked with a reference I liked, and it’s stuck.
I doubt you really need me to explain why I chose my user name.
well I normally use Dobraine in most online things. hes a char from robert jordan novels. but since everyone just shortened it to Dob when they talked to me, I just use that now. Course now everyone thinks Dob = date of birth!
I don’t have very high self-esteem.
Mine’s from the science fiction movie of the same name.
“Cheese sandwich…pretty…”
The evil villain from the Danger Mouse cartoon series. Actually it is Baron Silas Greenback but I didn’t want a really long user name.
My initials are CAB so taxicab was my preferred name 5+ years ago, but that was taken more often as more people got online so I inserted '78 (the year I was born) so I could come up with a unique name. So far it’s never been taken on any site before me. (So generally speaking, any taxi78cab you encounter is probably me!)
Here is one old thread on the subject . It’s a little old so I will paste my answer here.
Sam was my father’s nickname for me when I was little. The numbers are a convolution of my birthday