Annie, I believe it's called an "alias". Ok, say, "Alias". There, good job. Oh, and congrats on your first post, don't make it your last!
snotmare was an original alias that I cannot take full credit for. My long time friend Mr Reece helped me come up with it one fateful day at laser quest. Here's the short version... picked nose in grade school -> got made fun of, called me "bugger", "snot", etc. I hated it. -> high school, name continued, still hated it. -> went to laser quest, needed alias, something that would be fitting -> Reece and I throw out ideas, eventually come up with "snotmare" -> I hated it -> 2 minutes later I loved it -> now it's me.