Over 5,000 years ago, a rogue faction of Kree came to Earth, as part of a project to genetically alter humans to create physically enhanced soldiers to fight their many wars. While they employed the same process on many worlds, their experiments only had great success with human subjects.
However, following discovery by the Kree Empire and an insurrection by one of their own creations, the Kree were forced to abandon the project. One such Kree, through unknown means, became stranded on the planet and, at some point, perished.
This Kree was found by HYDRA and taken to a stronghold amongst various other objects of Kree origin, including the Diviner. In 1945, HYDRA was defeated and the corpse was confiscated by the Strategic Scientific Reserve. It remained in their custody until the formation of S.H.I.E.L.D., when it fell into their possession.
The bodily fluids of the Kree, which had been named the Guest Host, were later found to have highly potent regenerative capabilities. Under the orders of Nick Fury, the corpse was relocated to the Guest House, a former World War II bunker. Its bodily fluids were harvested and used to create formulas such as GH.325, as part of Project T.A.H.I.T.I., with the prime intention being to ensure the continued survival of the Avengers in the event that any member of the team were to perish.
Agent Phil Coulson was charged with heading the operation, but after the formulas that were harvested from the G.H.'s body proved to be dangerous to the participants, the project was shut down. It was almost immediately reinstated after Coulson was killed by Loki, an invading Asgardian, and Fury had Coulson undergo a procedure in which he was resurrected by GH.325. However, Coulson's memory was erased to ensure he would not remember the traumatic procedure, and as a result forgot completely about his involvement with Project T.A.H.I.T.I.
Coulson later rediscovered the Guest House when he and his team infiltrated the facility, hoping to use the GH.325 to revive one of his team members, Skye. Inside, he found the G.H. corpse being preserved in a stasis pod, and was left clearly disturbed by the discovery. Shortly after, the Guest House activated its auto-destruction failsafe, destroying the base and all of its contents, including G.H.
- Kree Physiology: As a Kree, G.H. possesses all of the various superhuman attributes common among his people, such as superhuman strength, durability, agility, and an efficient healing factor.
- Superhuman Strength: Like all Kree, G.H. is superhumanly strong and possesses greater physical strength than any normal human being.
- Superhuman Durability: G.H.'s body is more resistant to physical damage than the body of a normal human being.
- Superhuman Agility: G.H. naturally has greater agility, dexterity, balance and body coordination than a normal human being.
- Regenerative Healing Factor: Like all Kree, G.H. possessed powerful regenerative abilities, far stronger than that of any human. G.H.'s healing factor was so potent that S.H.I.E.L.D. was able to use his body to heal and resurrect their agents thousands of years after his death.
In chronological order:
- Agents of S.H.I.E.L.D.