"When the going gets rough, they need more than a pill-roller. I'm their main man!" — Doc

   After graduating from Harvard Medical School, Doc completed his residency at Johns Hopkins. When he enlisted in the Army, Doc hoped he could be guaranteed a spot on the G.I. Joe team. He was told the Army didn't make that kind of deal, but he continued on anyway. Doc considers himself a pacifist, but saw a position in the military as a way to do something that made a difference. Thus, he graduated Airborne School, Mountaineering School and the Desert Training Unit. He soon gained a reputation for working in dangerous situations and spent a lot of time on medevac choppers.

    It was as a medevac medic that Doc first began to work with the G.I. Joe team, though not as an official member. Doc was involved in the mission during which Snake-Eyes was disfigured in a helicopter crash. Doc told Hawk that Snake-Eyes shouldn't be allowed to continue the mission, but the wounded commando convinced Hawk otherwise. Doc often worked with the Joes, and years later Hawk had him assigned to the Joe team as their permanent medic.

    On his first mission as a member of the team, Doc traveled to Alaska where the Joes were trying to stop Cobra's attempt at poisoning the Alaskan pipeline. Though he carried no weapons, at one point Doc struggled with Cobra's mysterious "specialist", and stalled him long enough to assist the team. The specialist was later revealed to be Destro. Though Doc didn't fare to well in the fight, he later joked about "beating that Cobra about the soles of his boots with my face." Doc continued to participate in many missions around the world, including a rescue mission in Sierra Gordo, a battle in the middle of Washington DC, and a fight against Cobra in the Florida Everglades.

    Doc and a few other Joes were on what was supposed to be a simple drop-off/pick-up operation in the Gulf of Mexico. Their freighter, the Jane was spotted by Cobra Rattlers, which attacked the ship. With limited crew and weapons, the Joes tried to defend themselves. Contending with enemy fire and a shorted-out electric cannon, the Doc and Tripwire managed to repair the damaged guns and shoot down the last Rattler. Unfortunately, it was too late. Fires had broken out on the Jane and the Joes had to escape the sinking freighter. They were eventually rescued by the Joes they were supposed to pick up.

    Some time later, Doc and many other Joes returned to the Gulf of Mexico in the Tactical Battle Platform. While battling Cobra hydrofoils, the Joes uncovered an underwater Cobra base that was killing of sea life in the area. When Doc heard that the Pentagon was considering dropping a nuclear weapon to destroy the underwater bunker, Doc was upset. Soon, he came up with a plan to use an amount of conventional bombs with a power equivalent to a nuke. The plan destroyed the bunker, but avoided any nuclear radiation. As it turned out, Cobra's bunker was just a ruse to get the Joes to aggravate a faultline under the ocean floor, which caused the creation of Cobra Island. In the battle that followed, Doc remained to treat the wounded. A short time later, Doc discovered that Zartan had infiltrated The Pit disguised as Ripcord and later Snake-Eyes. Doc then was one of the many Joes to participate in the invasion of the Cobra-controlled town of Springfield. For the next few years, Doc continued on with the Joes and taking part in many important operations, including the Joes involvement on the Cobra Island civil war.

    Doc's final mission began as a supposedly simple raid on Cobra Terror-Dromes in the desert nation of Trucial Abysmia. The mission went sour when the Joes stumbled upon a large contingent of Cobra soldiers and vehicles. The team was captured and held prisoner by Cobra. A SAW-Viper, misunderstanding orders, killed several of the Joes in cold blood. The unarmed Doc was the first. He and his fellow Joes were given heroes' funerals in Arlington National Cemetary.

    Doc never regretted his time with the team. As he once said, "the G.I. Joe team is the best we have. We send them into the worst situation imaginable because that's where we need them most. When the going gets rough, they need more than a pill-roller. I'm their main man!" Many years after his death, Doc's niece Carla Greer joined the latest incarnation of the G.I. Joe team, using the code name "Doc" to honor her uncle. She first worked with the Joes during the global conflict known as World War III.