Although Jerry makes his first appearance in a Atlas horror/mystery comic, he later got a more prominent place in the Marvel Universe as part of the villain group known as " Headmen". Due to an experiment gone wrong (trying to replicate the Pym-particles witch made Henry Pym the Ant Man) Jerry's bones became extremely small and thus gave him a grotesque appearance. Angered and bitter, Jerry sought revenge on the world. He fought the Defenders numerous times, and even with his somewhat silly appearance, he is a person to be dealed serious with. At one time, when the newly reformed Defenders where away from earth his group managed to invade a large part of America. During this time, Jerry sought out all those whom had wronged him in the past, including bullies and even girls who didn't want to date him. He had them reduced to miniature size and let them get slaughtered by his laboratory-rats. Even with these crimes, Jerry and the Headmen managed to stay out of the hands of the law.
Some time later, he and his team also fought the newly reformed Heroes for Hire team, where there was one casualty to grieve, namely Heroes for Hire's newest recruit Orka. A reprogrammed Doombot shot a hole through his chest. After this, the Headmen fled, and nothing has been heard from them since.