Once the lab assistant of Doctor Bruce Banner, Samuel Sterns sabotaged the original gamma reactor experiment that created the Hulk. Later caught in an explosion of toxic gamma waste, Sterns was transformed into a maniacal genius, the Leader. Wanting to steal the Hulk's incredible strength for himself, the Leader has become his arch-enemy. Planning to use their combined power to take over the world, the Leader will stop at nothing to capture the Hulk.