Voiced by David Webster (2002) and Steve Von Wormer (2007)
"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."
A former Marine, Billy was wrongfully sentenced to execution for the slaughter of 23 people in Africa. However, when his transport through the Arklay mountains was overrun by mutated leeches (No, seriously...), he escaped. He proceeded to team up with Rebecca Chambers, and the two investigated zombie filled trains and a research facility in the woods. He was last seen in the woods around the mansion area, and hasn't been heard from since.
Hidden Depths: Despite how brutish he seems more often than not, he's remarkably good at playing the piano.
Tip of the iceberg. When Rebecca finds him after he gets washed away, they come upon a pile of skeletons. Somehow Billy is aware that Marcus used them as test subjects for the Mother Virus. Someone knows a little more than they're letting on.
Huge Guy, Tiny Girl: One of the brawniest male characters, partnered up with the smallest adult female character.
Possibly averted, as Word Of God states that they plan to have him return in the future.
Jade-Colored Glasses: Billy is almost bizarrely aloof about his conviction, resigned to his fate, and cynically shoots down Rebecca when she tries to be optimistic about it. And yet...
Knight in Sour Armor: ... The cynical, wrongfully convicted murderer has a powerful sense of justice. He's the one who convinces Rebecca to partner up with him and he's the one who refuses to go back on his word.
Tattooed Crook: Averted. He's the only convict among the series protagonists and has a very prominent tattoo, but Billy is a decent guy and not actually a criminal, and closer examination reveals that his tattoo reads, "Mother Love."
One of Umbrella's three founding members, he was murdered by Wesker and Birkin on Spencer's orders. He returns in Resident Evil Zero, where it's revealed that he is the one responsible for the Arklay Mountain and Mansion outbreaks.
The Villain Makes The Plot: His actions after death lead to the original Resident Evil, and the entire series as a whole (which prompts Chris Redfield to leave for Europe after 6 months, Claire looking for him, Leon's involvement, etc)