Eddie March was a successful boxer until a serious blood clot forced Eddie to retire. Happy Hogan was able to get him a job with Stark Industries, and Eddie eventually became trusted enough to where Stark revealed he was Iron Man. Tony's strain on his heart was causing him to consider finding someone to replace him, and Eddie volunteered. He trained with Stark for weeks, and a hotline was set up so Tony could call him whenever he was needed
Eddie was briefly turned into the Freak, an unintentional side-effect of Stark's 'Enervation Intensifier Ray', intended to accelerate healing and vitality.