Call of Duty first featured its now classic Zombies mode in Call of Duty: World at War, and its remained a core component of Treyarchs game ever since. Call of Duty: Black Ops 6 seems to be following suit, as recent COD leaks about Zombies have given fans some hints about where the game might go. Thanks to the hype the Zombies mode generates with every Call of Duty release, it's as important as ever to see how the series innovates next.