Popcorn is an achievement/trophy in Call of Duty: Advanced Warfare in Exo Zombies. It requires the player to kill fifty zombies with the Magnetron in Infection.
You can unlock the Popcorn medal in CODM by using a grenade to eliminate two or more enemies at once in a multiplayer game. Call of Duty Mobile players cannot achieve this medal in Battle Royale mode. This is because this medal is a unique MP Achievement.