When I started playing Diablo 2 (around age 12-13), I wanted a new name that wasn't named after a Pokemon (my name was Pika, by the way), since by this point the gigantic Pokemon fad was going out of style. I had learned about Diablo 2 from my cousin, who at the time went by the name SlyFoxxx. So, I sat in my room trying to think of names that I could use, when I finally decided to imitate my cousin's nickname. I was kinda obsessed with alliteration, so after coming up with a few candidates, I finally decided to go with FuriousFox. I've stuck with it ever since.