William Birkin (Resident Evil Zero)

Umbrella's youngest ever researcher when he first started, he has a passion for his work and as such neglects his family. Once he took over the research of James Marcus with fellow researcher Albert Wesker, he moved to the Spencer Mansion laboratory and perfected the T-Virus. During his time at the Arklay facility he discovered the G-Virus, and quickly requested plans for a laboratory to be built underneath Raccoon City so he could further his work in this new mutagen.

His role in this game is not very big, he simply appears alongside Albert Wesker as they are taunted by an unknown person who appears to be a younger version of the late James Marcus.