The story of anabus
When I was younger (middle school), I subscribed to the magazine EGM. In one issue, I read their preview of Xbox Live. They wrote that AnubisMaximus would be a cool GamerTag.
Several months later, I played Halo for the first time with some friends, and I needed a name for my profile. I remembered that article and thought, "I'll use that name they liked." However, I didn't remember correctly, typing in anabus (Halo's technical restrictions did not allow the entire "anabus maximus" I would've liked).
Later, after discovering the joy of multipayer computer games like Jedi Outcast, Battlefield 1942 and Starcraft, I added the underscore to form anabus_maximus. For a while, I used it as my username many places.
Eventually, I dropped the "maximus" of the name and started to use just anabus for usernames around the web. I still do this sometimes, but I also use the usernames stumand tjstum.