William O'Brien
From Halopedia, the Halo wiki
[[Fil:Bill OBrien.jpg|thumb|Screenshot from ViDoc: Et Tu Brute, camera opens on a table with four Bungie staff being Interviewed from left to right are Nathan Walpole, John, Bill O'Brien, and Jeremy]]
William O'Brien is an American animator, artist and video game producer. He is also a current employee of Bungie Studios. Born and raised in Boston, Massachusetts, USA, he attended art school and majored in animation. He specializes in both 2D and 3D animation.
He was credited as one of the animators for Halo 2.
Trivia
O'Brien had an ODST don his name in the short, Another Day at the Beach. The ODST died in a Pelican crash during the events.