World at War (2008)\n\n The fifth Call of Duty installment, World at War, was the official introduction to the famous Zombies mode. This is where Nazi zombies originally came from. World at War's Zombies were not campy, and just genuinely terrifying.

Call of Duty's staple game mode, Zombies, was initially a fun game mode, with no future in sight. That was until the credits rolled for gamers in Call of Duty: World at War, and fans were introduced to the zombie horde.