Iron Man: The result of his father's experiments, Tony Stark possesses neural tissue throughout his body - making him one of the smartest men in the world. After adapting his father's biotech armor for long-term use, he joins the Ultimates as Iron Man!
Hulk: After injecting himself with the experimental super-soldier serum scientist Bruce Banner transformed into the monstrous Hulk! Eventually able to control his alter-ego, the Hulk continues to fight as a hero when not hiding from the world that hates him.