Chickens appear in Call of Duty 4: Modern Warfare, Call of Duty: World at War, Call of Duty: Modern Warfare 2, Call of Duty: Modern Warfare 3, Call of Duty: Black Ops II, Call of Duty: Ghosts and Call of Duty: Black Ops III. They appear in very small cages, flapping their wings and clucking. If shot, they will let out a squawk, spin round, and die in a flurry of feathers and blood.
Cages with chickens appear in Call of Duty: United Offensive in the campaign mission Sicily 2 during the chase. If these cages are hit by a vehicle, chicken noises will be heard, and blood and feather particle effects appear. However, there are no chickens visible inside the cages.
The chickens are there mainly in the game for cosmetic and comedic purposes and do not count for any momentum for killing one:
- In Call of Duty 4: Modern Warfare, they appear briefly in the level "The Coup" when Al-Fulani is dragged into the car.
- In Call of Duty: World at War, the only chicken to appear is a dead one in the butchers shop in "Upheaval". If shot, it will fall from the wall.
- In Call of Duty: Modern Warfare 2, chickens appear in the level The Hornet's Nest and the Special Ops level Bomb Squad in cages at the marketplace. They also feature on one the emblems for use on the callsign.
- In Call of Duty: Black Ops, they appear in "Victor Charlie", they are seen running away from gunfire before the player reaches the Rat Tunnel. Chickens also appear as a Power-Up in the Zombies level Dead Ops Arcade. They also appear in the DLC map Kowloon and cannot be killed in it.
- In Call of Duty: Modern Warfare 3, chickens were first seen in the multiplayer trailer. During one of the Create-a-Class scenes, a chicken is seen with the text "CHICKEN" underneath. Several chickens are seen near the well in the multiplayer map Seatown, in cages in the multiplayer map Bootleg, a motionless one operating the crane on Overwatch, and a live one in the house on Vortex.
- In Call of Duty: Black Ops II, they appear in mission "Time and Fate".
- In Call of Duty: Ghosts they appear on the Invasion DLC map Departed and the Nemesis DLC map Dynasty.
- In Call of Duty: Black Ops III they appear again as a Power-Up in the Zombies level Dead Ops Arcade 2: Cyber's Avengening. This time, they are more plot related as the main character's objective is to defeat the Cyber Silverback and rescue his chicken.
- The "Colonel Sanderson" achievement is a direct reference to the KFC line of restaurant's owner, who was called Colonel Sanders, as well as to Roach's last name being Sanderson.
- In "Call of Duty: Modern Warfare 2", it is possible to earn three titles for the player's callsign with chickens running away from bullets.
- In the Wii version of Call of Duty: Modern Warfare 3, the chickens are only killable with explosives.
- Chickens in the Modern Warfare 3 map Seatown will not explode normally when stuck with Semtex grenades, but will instead emit several feathers, spin around, and then die.
- In Call of Duty: Modern Warfare 2 and Call of Duty: Modern Warfare 3, when given the opportunity to Prestige, if the player opts out and decides not to prestige, the sound of a chicken squawking is used to imply the player is 'chickening out'.