When the two discovered Robotnik's schemes to trap the Knothole Freedom Fighters in the Hall of Mirrors at Happyland Amusement Park, they left Robotnik and joined the Chaotix to help them stop Robotnik's plans. However, because Robotnik used Power Gems to power them, Heavy and Bomb developed consciousness and consciences. Heavy was created in 3235 along with his counterpart Bomb, both created to act as 'mechanical mechanics, designed to seek out and repair damaged systems automatically'.
