Prior to the events of "The Return of Optimus Prime" set at sometime in either the 1st or 2nd Season, Gregory Swofford was a young human scientist who encountered a fight between Optimus Prime & Megatron. Due to Megatron's interference, Gregory was injured & scarred during the fight & then holds a deep grudge towards the Cybertronian race, particularly Optimus whom he blames, after this encounter.
Years later, Gregory Swofford & Jessica Morgan were conducting tests on experiment heat-resisting alloy on a star, until they discovered an Autobot ship carrying the body of Optimus Prime. Despite his hate towards the Autobot leader, he helped Jessica after the latter convinced him to pull the ship away from the star, not before he kicked Optimus' arm, calling him a "lousy robot".
As they returned to Earth, Gregory noticed strange spores coating on their ship. Upon arriving on Earth, he & his colleague Mark Morgan, Jessica's father, discovered its hate inducing properties after testing it on two lab rats. Their experiment is cut short when the Decepticons attack their lab, injuring Jessica & crippling her. After she was taken to the hospital by Protectobot First Aid, Swofford & Morgan are driven by their hate of the Cybertronian race, inspiring Swofford an idea to use Optimus' body as a bait to the Autobots.
Swofford accompanied his colleague to the hospital to retrieve Jessica, who is now earing mechanical prosthetics. Instead of being thankful to the Autobots, Dr. Morgan furiously blames them instead & brought her home with Swofford in the tow as well.
Upon failing to reactive Optimus, Morgan & Swofford then decided to melt the Autobot leader's body in the furnace. Jessica, who is now allied with the Autobots, tearfully demanded him to stop, only for the latter to reveal he had already planned using Prime's body as bait to lure the other Autobots into their trap: by unleashing the Hate Plague on them. The plague soon infected everything on its path as it infects not only Transformers but as well as humans & various lifeforms, & possibly including Swofford & Morgan as well offscreen.
After a ressurected Optimus destroys the Hate Plague, Swofford was among the infected victims freed from the infection. Despite being the cause of the ruckus, Swofford apologises & Optimus pardons him, on behalf of Jessica.
- Alongside his colleague Mark Morgan, they are both very similar to James Savoy as they both hated the Cybertronian race regardless of faction for being the cause of their loved ones' demise. Unlike both of them however, Savoy never redeems himself and both Morgan and Swofford themselves lacks yangire-like qualities that Savoy possesses.