People say Zombies is only a Treyarch thing, but every COD studio has worked on Call of Duty Zombies in some capacity, even more recently. I'm going to list everything each Non-Treyarch COD studio helped develop for COD Zombies. Some of this isn't 100% confirmed, because we don't always have the exact information on it, but a lot of it is confirmed or at least is heavily supported. Infinity Ward: - Infinite Warfare Zombies - The Haunting in MWII DMZ - Extinction (not Zombies but it's Zombies-adjacent) Sledgehammer Games: - World War II Zombies - Likely assisted with Exo Zombies & Vanguard Zombies - Took over development of MWZ post-launch - Included a lot of Zombies content in Modern Warfare III's Multiplayer (Vortex maps, Ray Gun Game Mode, Hordepoint, etc) High Moon Studios: - Support studio on many Zombies games and maps (including BO4, BO6, BO7, MWZ, and potentially a few others) - Officially credited for working on Classified, Alpha Omega, and Tag Der Toten - Officially confirmed to have developed Totenreich in partnership with Treyarch, which means they likely made a lot of that map Raven Software: - Led development on Exo Zombies - Cancelled Standalone Zombies game in 2011 - Call of Duty Online Zombies - Warzone Haunting Events - Assisted development on older Zombies titles such as Black Ops 1 - Supported development on MWZ Beenox: - Warzone "Rebirth of the Dead" Mode - Supported development on MWZ