Clarence (Earth-5875)

Clarence was an Auton synthetic of the Office of Naval Intelligence Section III, who was stationed as a sleeper agent aboard the prowler UNSC Red Horse in October 2552 as a part of Sergeant Zhao Heng Lopez's Marine squad.

Skirmish on the Mona Lisa
As a member of Sergeant Zhao Heng Lopez's Marine squad aboard the UNSC Red Horse, Clarence later participated in the reconnaissance mission aboard the prison ship Mona Lisa. Unlike the rest of the squad, Clarence was fully aware of the true purpose of the mission, and was ordered to ensure none of the Marines escaped the vessel with information regarding the xenomorphs. After a brief encounter with unarmed and unarmored sangheili, the Marines were ordered to carry the Cole Protocol, splitting in two teams, of which Clarence was placed into Corpsman Ngoc Benti's command alongside Maxwell Gersten, Leslie Orlav, and Quincy Tsardikos.

When the Marines passed through the recycling plant of the Mona Lisa, they were attacked by a xenomorph horde. A Facehugger spat acid into Orlav's face, killing her, and also injured Gersten. He was then shot and killed by Clarence without hesitation, as he feared the xenomorphs were infectious and contagious, citing Gersten being alive was a threat to them, to which Benti lamented. While moving further, the surviving Marines encountered a neurotic prisoner, Patrick Rimmer, and a surviving sangheili who temporarely sided with Rimmer to survive, whom he called Henry. As they continued walking, Rimmer explained what he knew of the xenomorphs and the events that happened aboard the Mona Lisa.

After arriving in the engine room, the four witnessed the Marines' D77-TC Pelican pilot Karina Burgundy being dragged to a massive hive the xenomorphs constructed to build a Proto-Keymind, as the aliens planned to use the ship's Shaw-Fujikawa Translight Engine to spread to other planets. After hearing Lopez chatting with Commander Tobias Foucault, Benti killed the Proto-Keymind with two fragmentation grenades. They then rushed to meet with Lopez and James MacCraw to escape in the ship's two remaining shuttles.

As they rushed to the shuttles, Benti was gravely injured by a xenomorph Aggressor, but was picked up by Henry, who saved her life twice. Once they reached the airlock, Clarence shot Rimmer, and revealed himself as an undercover Auton sleeper agent. However, before he could proceed with his plan, Benti sacrificed herself by pushing both her and Clarence at an incoming xenomorph horde.

Personality
Clarence was quiet and overly serious, to the extent his silence disturbed Sergeant Zhao Heng Lopez and the rest of the squad. He was an aptly skilled combatant, being the best among all of the Marine squad. Ngoc Benti described him as someone she could count on, as Clarence was well adjusted to lead with multiple situations, even those that were unknown to him.

Owing to his nature as an Auton synthetic sleeper agent, Clarence was completely dedicated to his mission and loyal to the directives of the Office of Naval Intelligence. Despite this, he showed compasion when betraying his teammates, saying he was merely following orders and that their deaths were not personal.