In my, err, numerous years of online gaming I'd recommend two things.
1 Never name yourself after a game. It instantly associates you with that game and any fans of other games in the same genre will no doubt abuse this.
2 Make sure you pick your own name. Having someone or something pick it for you means it's not your identity. It's a random set of letters thrown at you by someone you possibly don't care about.
Having said that CosmicCowWow is fairly generic and quite fun.