Mark Morgan is the secondary antagonist from the original G1 Transformers. He is Jessica's father and a corrupt scientist who hates Transformers regardless of faction and serves as one of the main antagonists of the two-part season finale of Season 3 "The Return of Optimus Prime".
Like his partner Gregory Swofford, Morgan was ultimately corrupt. Mark Morgan was in charge of sending his daughter Jessica and his colleague Gregory Swofford across the universe to conduct tests on experimental heat-resistant alloy near a star. The mission was a success, but however, Jessica and Swofford home two other rediscoveries: Optimus Prime's body and a sample of red spore.
In the laboratory, he and Swofford tested the red spore on two lab rats, discovering its hate inducing properties. He was about to dismiss his daughter's warning of the spores getting loose when their lab lab was suddenly attacked by the Decepticon dragon combiners, the Terrorcons, who came for the heat-resistant alloy. Morgan was about get crushed by falling debris, only to be saved by his own daughter, who was crushed instead thus crippling her. The Technobots soon arrived, fought off the mechanical dragons and saved Jessica. Despite the Autobots' best efforts, he blamed the attack on every Transformers. Morgan then conspired with his colleague Swofford into using Optimus Prime's body and the Hate Plague to destroy every Transformers regardless of faction.
As the doctors tried to save Jessica's life, Morgan worked hard to revive Optimus, only to fail as well. He soon visited his daughter, only to his horror as she is surrounded by Protectobots, who gave her mechanical prosthetics. Morgan paranoidly claimed they have turned his daughter into a cyborg and took her home immediately. Unable to revive Optimus, Morgan and Swofford tried to melt the Autobot leader's body, only to be stopped by his own daughter, who tearfully pleaded. Instead, he decided to use his own daughter, who is an Autobot ally, to lure the Autobots into their lab.
After Jessica alerted Rodimus, the Autobots soon rushed into her father's lab with caution. Ultra Magnus and the Aerialbots, however, fell into Morgan's trap and ended up being the first infected victims of the Hate Plague. This soon started to infect other Autobots in the area as well. Morgan himself threw a canister of Hate Plague spore on Rodimus but missed. The Hate Plague soon spread on the entire universe as it infects not only Transformers but as well as humans and various lifeforms across the universe, presumably including Morgan and Swofford as well offscreen.
After the Hate Plague was wiped out by a revived Optimus Prime, Morgan was soon freed of the infection. He tried apologizing to Optimus, but Galvatron, in a rare moment of calm, walked towards (as he pushed the two aside) and thanked Optimus for stopping the plague which allowed Optimus to refuse Morgan and Swofford's apology for good. It isn't stated what happened to Morgan and Swofford but it is indicated they were imprisoned for their actions. And his labarotary is likely to be demolished by the authorities as well.
- Alongside his colleague Swofford, they are both similar to James Savoy as they both hated Transformers regardless of faction due to being the cause of their loved ones' demise. Unlike Morgan and Swofford however, Savoy never redeems himself and has Yangire-like qualities that both Morgan and Swofford lacks.
- Morgan is very similar to Hiroshi Sato as they are both important figures who racially despise a certain powerful race for being the cause of their loved ones's suffering and are both fathers with a daughter.
- Mark Morgan and Gregory Swofford are the most hated characters in the Transformers series due to their petty hatred nearly causing the apocalypse as well as that the episode not explaining if they were punished or not. But thankfully, Prime refused their apology when Galvatron walked towards (as he pushed the two aside) and thanked him for curing all of the civilization.
- Despite both being scientists, they seemed to dislike advanced technology.
- Despite caring for his daughter, he lied to her about getting rid of the plague and continually ignored her demands to stop hating the Autobots.
- Morgan and Swofford are the second human antagonists that Optimus refused their apology in the end. The first was Shawn Berger.
- They are also the most corrupt scientists in the series.