Number 4 (Big Guy and Rusty the Boy Robot Animated)
A member of the Legion ex Machina. Number 4 pursued Rusty through the Internet and was bested by him. After being restored, he engaged Rusty in a battle of minds and wound up exchanging several of his personality traits with the other robot. He was captured when he reclaimed his personality.
His head was stolen by Pierre Donovan and placed on a robot built for his school science project. He escaped and was being pursued by all sides, including the rest of the Legion, who wanted him destroyed for his incompetence. He was destroyed while trying to destroy New Tronic City.