Billy and Jimmy, or Billy or Jimmy, could make for fun characters to play as in a future SMBC update. Either DD 1 or DD 2. Maybe they could be part of Ryu's alternate skins. They don't normally scale walls, but that can be removed or kept. Their throw attacks could be some of the weapons you find in the game. It would be cool if you could throw goombas, but I understand that might make these guys unattractive as possible candidates since that would require more coding.