O is a letter. He is a member of ABCDEFGHIJKLMNOPQRSTUVWXYZ. He is the member who is least of a square, but he sure is stupid. H and ! are constantly having to help O understand the most basic concepts.
O is the twin brother of 0. Because of this, he gets to say he is 0 sometimes, which is illegal. O so during moments of frustration.metimes thinks he is 0, so then H slaps him and ! kicks him, and he says "OH!" H and ! then walk back to the corner to wait for another moment of stupidity.