I used to work at a restaurant and in our break area out back there was a pigeon that would hang out there. And he was greasy looking ,and crazy. We would give him some bread, and he would eat some and freak out. So we called him GreasyPigeon. Then one we found him dead in the grease trap.
When I was 13, I was trying to come up with a username for Starcraft, and I had just finished watching The Evil Dead, but since "Necronomicon" is, in fact, a noun, it wouldn't have sounded right.
So I just changed it to an adjective.
Also, I am nostalgic and don't like to change my username for anything.
It was the name I gave to a pet fish of mine who was previously known as Spot. I had an aquarium of about 10 fish at the time and had asked my neighbors to feed them while I was on vacation. Much to my surprise, I returned to find a massacre in my fish tank. My neighbors had forgot, and the fish turned to cannibalism. All but one remained, Spot. After this I dubbed him Solo as he was the last fish standing and swam alone amongst a tank full of death. I later replaced the "l" with a "1" to look 1337.