From Halopedia, the Halo wiki
Eric S. Trautmann is an American comic book author. He has co-authored several pieces of Star Wars literary references from 1992 to 1998. In 1999, he became the content developer for Microsoft Game Studios Franchise Development Group (MGSFDG). where he co-authored a number of story bibles for a variety of Xbox such as Crimson Skies, MechWarrior 4 and Halo.
During the writing of Halo: The Fall of Reach, Bungie almost cancelled the novel but was convinced by Trautmann to approve it in exchange for himself, Matt Soell and Brannon Boren writing an estimated "80 percent" of the in-game dialogue of Halo: Combat Evolved. The dysfunctional relationship between Bungie and the Microsoft team working on the game created some disconnect - the notorious "this cave is not a natural formation" line was caused by Bungie promising that the environment would not be immediately obvious as an artificial formation. During development of Halo 2, Trautmann and Boren argued for the inclusion of ODSTs in the game, although Bungie questioned their recognizability to fans and the in-universe role they served. During development of the Halo Graphic Novel, Trautmann set up a franchise group for Halo media and was told that Bungie were unhappy with the creative team, consisting of John Ney Rieber and Adi Granov, and was told by Pete Parsons that Bungie would rather have Alan Moore and Joe Kubert. He ended his involvement in the Halo franchise on November 9, 2004.
He is the author of the book The Art of Halo.