In 1988, Courtney Robert Haine was injected with a super-soldier serum called "Soldier-X" in an experiment conducted by the Speculative Human Engineering Division of the O.S.I. The serum increased his strength, endurance, agility, and aggression with the unfortunate side effect that it decreased empathy and caused him to develop pedophilic tendencies. The resulting O.S.I. soldier took the name Sergeant Hatred and quickly became a double agent for The Guild of Calamitous Intent.
When Sergeant Hatred retired from The Guild and returned to the O.S.I., they attempted to cure his pedophilia with an experimental drug called Nomolestol. The drug initially curbed his desire to molest children, allowing him to serve as bodyguard to the Venture family despite their having two teenaged boys whom he had previously molested in his supervillain days.
At one point Sergeant Hatred ran out of shots of Nomolestol, causing him to backslide in a crowded movie theater full of children and rush home to the Venture Compound's panic room in the midst of a nervous breakdown. He was ultimately calmed down when Hank Venture disguised himself as his ex-wife Princess Tinyfeet, luring Hatred out of the panic room so Henchman 21 and several other henchman of The Monarch could shoot him with tranquilizers.
Sergeant Hatred develops severe gynecomastia as a side effect of the hormones in Nomolestol interacting with the Soldier-X serum in his bloodstream. Hatred's bust size reaches at least 48DDD as a result and he begins to wear a bra. The discomfort eventually causes him to seek breast reduction treatment from the doctors at the O.S.I.
The Nomolestol treatment appears to have been successful with Sergeant Hatred, as he currently gives daily guided tours to Boy Scouts and other children who visit VenTech Tower and has not apparently had another pedophilic episode.