When I was 11 I heard about runescape and I wanted my username to be something with Wolf, because this is my first name in real life. So I tried TheWolf, MadWolf, BadWolf, CrazyWolf, StrongWolf, HeroWolf but they all where taken
I stuck with MadWolf and runescape suggested some numbers because it wasn't available. 0MadWolf0 and 8MadWolf8 where taken too and to make a huge story long I choose Mad_Wolf80.
After like 2 or 3 years I was able to change my name and I made it TheMadWolf, because it was available now.
I used it on wow, gta, saints row, mw and for every other gamers tag, game name or whatever on the internet.