Rookie

The Unnamed Marine is a UNSC Marine Shock Trooper, and served in Mombasa, Kenya in 2552. He/she is the only known survivor of his/her unit after the Prophet of Regret's slipspace jump devastated the city and Shock Troopers still conducting the drop.

Halo 3: Recon
Contrary to popular belief, he/she could not be the SPARTAN-I mentioned in 'PARDON OUR DUST' as he/she was of Lance Corporal rank.

He/she must of been extremely hardy to have survived a drop and crash with a 99.99% expected fatality rate (later corrected to 00.52%), with only battered armor and a 6 hour period of being unconscious in his/her HEV to show for it. At the time of impact, the Superintendent displayed the message "Motor Vehicle Crash!" and when searching for the debris though the smoke, the SI displayed "Acquiring Vehicle ID..." As a Civilian Infrastructure AI he/she would not have known a HEV pod is and assumed it was a vehicle, later also trying to get the vehicle ID for the Type-52 Phantom that came searching for the Marine and then calling the New Mombasa Police Department when unable to get its ID. After blowing the hatch off his/her pod, the Trooper ducks into hiding to avoid the probing lights of the Phantom, and a patrolling Jiralhanae pack. The Superintendent activates a set of signs and lights a row of streetlights, showing the Trooper a safe path away from the patrol.

Trivia

 * He/she is the main character of Halo 3: Recon, a prologue and expansion pack to Halo 3, due out in Fall 2009.
 * His/her main weapon is a modified Suppressed SMG with a red dot sight and a laser module.