Hidden Marine

Swamp
The Unarmed Marine is a hidden Easter Egg on the level 343 Guilty Spark. His character model is that of Private Mendoza, and was simply left behind by Bungie when they were making the game. He can be shot and killed, just like any other Marine.



To find him, you must first stay inside the Pelican that drops you off at the beginning of the level. You can do this by throwing grenades as soon as the game allows you to do so. This will allow you to stay inside the dropship as it flies away. After it travels a certain distance, the Pelican will drop you off and you will be outside the level barriers. After exploring around, you will eventually come across the Marine.

Sometime when you're inside the structure, bodies will spawn all around where you came in from. Sometimes (if not always), if you surface just before the Jenkins Cutscene, bodies will spawn all around and the Unarmed Marine's body will be where you fought the first Covenant on the level. If somehow you manage to get to the higher level after doing the trick above, Flood Combat form's corpses will be around the spot where the Unarmed Marine is standing.

Hallways
A second lone Marine can be found in one of the square-shaped hallways during Master Chief's escape. Unlike the other Marine found in the swamp, he will be carrying an Assault Rifle and his character model animation may change. It is unknown as of why Bungie had put him there, or what triggers this glitch. This Marine also has poor health just as the other Marines being attacked by the Flood under the light bridge were. It is a possibility that this Marine may have survived the ambush and taken cover in the hallway. The possibility of finding this Marine is highly unlikely, however.

Trivia

 * It is possible to, using the Bump Possession cheat, take control of the Marine and make him pick up weapons. Though Marines don't have Plasma Pistol animations, and thus can't pick them up, the Marine can pick up Needlers. There is an empty one on the ground below the cliff where the Marine is, and can be fired if the Bottomless Clip cheat is on.