Marcus

Marcus is a variant of the UNSC Marine face bitmap found in Halo: Combat Evolved. One can find it by opening a Halo: Combat Evolved map in Halo Map Tools. Not including Avery Johnson, there are six variants of face bitmaps. They are in DDS DXT1 texture format.

Trivia
To make the model for the Unnamed Bumblebee Pilot, Bungie artist Chris Hughes took Marcus and edited it to become female.