I do love the Harry Potter books, but apparently not as much as some. There is an entire Harry Potter Wikipedia devoted to characters and back story. That just seems a little weird to me. But if you want to find out everything you never wanted to know about this character, go here.
Of course X is also for xanthopsia which is a visual disturbance that makes objects appear yellow. As yellow is a happy color, I don't think I would mind very much.