Gammenon is one of the Celestials, and is sent out to find various plant, animal and humanoid specimens for experimentation. He reports to Jemiah and often travels with Eson. Gammenon is the Celestials' data collector and gatherer of specimens.
As part of the Fourth Celestial Host, Gammenon lands on Earth, where he is sighted by Ajak and Dr. Daniel Damian. Gammenon captures S.H.I.E.L.D. agents Tyler, Parks, and Stevenson, and reduces them to atoms. Gammenon allows Ajak to temporarily restore the captured S.H.I.E.L.D. agents.
Gammenon also encounters Thor, and then captures an airliner and its passengers, including Don Blake, S.H.I.E.L.D. agent Johnson, and Ereshkigal. Gammenon witnesses the transformation of Tyrannus by the Deviants's Flame of Life and his dissipation into space. Gammenon stood assembled with nine of the other members of the Fourth Host in Peru, and participates in the repulsion of the attack by the Destroyer, the Uni-Mind, and Thor. He then left Earth with the other Celestials.
Gammenon witnesses the near-destruction of the universe by a black hole created by Maelstrom.
Gammenon has an extraordinarily advanced knowledge of genetics and mathematics.
As part of the First Celestial Host, Gammenon used a gathering device composed of living metal which captures and tranquilizes specimens collected by Gammenon for study and analysis by his fellow Celestials. As part of the Fourth Celestial Host, Gammenon used a gather-rod, approximately 1,250 feet in length, holding in stasis a cluster of life-seed capsules containing the stored atoms of living organisms collected by Gammenon.