Billy Coen

Hey, Queenie! Feast on this!

Billy Coen is an American former U.S. Marine Corps Second Lieutenant-turned death-row inmate that escaped into the Arklay Mountains after the military transport vehicle escorting him was forced off the road by a pack of Cerberus. He took refuge in the nearby Ecliptic Express where he would later meet Rebecca Chambers, who had arrived with S.T.A.R.S. to investigate reports of murders in the vicinity.

Background
So, you seem to know me. Been fantasizing about me, have you?

In mid-1997, Billy was a Second Lieutenant in the United States Marine Corps with Force Recon, who, along with a team of Marines, were sent into hostile territory in Africa to attack a village used as a guerrilla training ground. Unfortunately, the air drop was off-target, and as such the team had to march across miles of hostile terrain to their target objective. The heat, combined with enemy attacks, soon reduced the team to four, and when they finally arrived, they found the village was actually full of innocent civilians.

Billy's commanding officer ordered the execution of the innocent villagers, and framed Billy for it, claiming, "one marine panicked under the extreme conditions and unintentionally killed the civilians." Upon returning to base, their base commander, Samuel Regan, had Billy court marshalled and sentenced to death. Flashback cutscenes in Resident Evil Zero imply that Billy didn't kill any of the civilians, but he neither confirms nor denies this to Rebecca.

Arklay Mountains
Listen, little girl, if you haven't noticed there's some pretty freaked out things on this train. And I, for one, wanna' get out of here. I don't think we stand a chance of doing it alone.

En route through the Arklay Forest to Regathon Base for his execution, the military transport vehicle used to take him there was forced off the road by James Marcus, and then Cerberuses attacked and mauled the MP's guarding Billy, causing him to run for his life. Billy then sought refuge in the Ecliptic Express, a stranded train, where he met Rebecca Chambers. Although Rebecca had been given orders to shoot Billy on sight (for S.T.A.R.S. believed he had killed the MP's), Billy persuaded her to work with him to survive. The two used their talents to pass through many of the obstacles they faced, and discovered the Umbrella Corporation's secrets.

Both were monitored by James Marcus, who sent various creatures to subdue them. Billy proved his loyalty by saving Chambers several times during the game, whilst Rebecca proved hers by saving him. Coen and Chambers eventually met Marcus. After revealing the details of his mortal demise, the leech residing in his body took control and mutated into the Queen Leech.

The two managed to temporarily subdue the creature, only to discover that a self-destruct protocol had been activated, caused by William Birkin. Matters became even more complicated when the leech returned. In the final battle, Billy fended off the Queen Leech while Rebecca opened the roof and exposed the leech to sunlight, thus making it vulnerable to attack.

Knowing this weakness, Billy acted as bait whilst Rebecca continued to open the roof further until there was no shade left for the creature to hide in. He proceeded to deliver a final shot with a powerful Magnum revolver, which instantly destroyed the leech. They escaped the crumbling facility shortly thereafter. In wake of the destruction, Rebecca allowed him to escape, by telling her authorities that he subsequently perished in the Arklay Mountains after their first encounter, keeping his dog-tags as proof. The two bid farewell as Rebecca heads to meet her comrades, while Billy escaped. Upon returning to Raccoon City after the Mansion Incident, Rebecca filed a report claiming that Billy had died during the initial attack that allowed him to escape, she went on to request a suspension of the case.