From Halopedia, the Halo wiki
Jeremy Cook was an production designer and art director at Microsoft Studios and 343 Industries. Before working joining 343 Industries to work on the Halo franchise, Cook previously worked at id Software, Industrial Light & Magic, and Blur Studio. As a member of 343 Industries' concept art team, he contributed several pieces of artwork for Halo Mythos. He contributed to the development of the Halo 4 Champions Bundle DLC Pack and Halo: The Master Chief Collection, and served as the lead art director for Halo Wars 2. Following the 2018 update on The Master Chief Collection, Cook produced a number of special backgrounds for the game's main menu. Jeremy Cook left 343 Industries in March 2019, and now works as the art director at Blizzard.