This is the name I use for forums and game avatars. There is a line from Futurama where KillBots are mentioned
Fry: I heard that one time you single-handedly defeated a horde of rampaging somethings in the something-something-system.
Zapp Brannigan: The Killbots? A trifle! It was simply a matter of outsmarting them.
Fry: Wow! I never would have thought of that!
Zapp Brannigan: You see, Killbots have a preset kill limit. Knowing their weakness, I sent wave after wave of my own men at them, until they reached their limit and shutdown. Kif, show them the medal I won.
I like playing shooting games, and I liked the idea that the only way to defeat me was by reaching a kill limit :p There is also the bit where I incorporated my real name into it as well