Easter Eggs

Easter Eggs are hidden surprises throughout the Call of Duty series. They are most prominent in Zombie Modes, in the games developed by Treyarch. Some are easy and can be achieved alone, while others require a great deal of cooperation. A lot of them, the most elaborate, can be used to gain an advantage either in a single player campaign or multiplayer zombies game, and some unlock achievements. Every Nazi Zombies map has a secret song which plays after activating a number of objects.

Note that map or level features that are distinctive or interesting, like the Porter Justice posters in the Modern Warfare games, the ghosts in the Zombie Mode maps of World at War, or the Brady Bunch house on Nuketown, are not noted here and can be found in the trivia pages of each map/level.

Campaign
Underground Passage: Ghostly room, Kaiser Bear, Sticky Bear, German dance party.

Operation Little Saturn: Giant Red Apple

Surrender at Aachen: Teddy Bear

Come Out Fighting: UFO House: Two hidden rooms, both with health packs, one with a UFO.

Depot Saboteurs: Sultan Room

Secret Wall: Contains health packs

Campaign
Cow : A giant cow in a hidden room.

Campaign
Little Resistance : Ray Gun : Use a raygun in the campaign.

Nazi Zombies
Nacht der Untoten: A radio which plays different songs.

Verruckt: Lullaby for a Dead Man (hidden song): Plays after flushing a toilet three times.

Shi No Numa: The One (hidden song): Plays after a telephone is activated.

Der Riese: Various easter eggs: This map contains a lot of different hidden surprises, including radio messages, the hidden song "Beauty of Annihilation", and a game of hide and seek (fly trap) which unlocks an achievement.

Campaign/Multiplayer
Teddy Bears: Various teddy bears are hidden throughout the single and multiplayer modes.

Video Game Case: In the mission No Russian, two cases which appears to be Modern Warfare 2 can be spotted as you walk up the escalators or stairs to a store on your left.

Main Menu
CIA Data System: A computer accessible from the main menu room allows you to browse the contents of a CIA computer and enter various cheat codes. This allows you to access Dreamland and play Zork, which unlocks an achievement.

Campaign
Numbers: Thundergun: Use a Thundergun in the campaign, simply on the first part destroy all Nova 6 barrels with a grenade or gun, there should be six of them, then go to the room on the right and find tho open tape dock. Hold X (it won't notify you) and continue to escape. When you reach the room with the wall of weapons, find the open tape dock, hold X again, it will close. If you did this right after a few seconds the screen should shake. Wait a few more seconds and hold X once again, you should now have obtained the Thundergun.

Multiplayer
Nuketown: Hidden song: If the heads of the mannequins are decapitated within 15 seconds, "Sympathy for the Devil" by The Rolling Stones is played. Requires multiple players to achieve. This may be hard, as the mannequins are randomly placed on the map every round, some might even spawn outside the map itself.

The names on the mailboxes are the names of the protagonists in the campaign, Mason, Hudson and Woods. They will also have other names on them, which may be of some of the developers.

The "Welcome to Nuketown" sign will change population according to how many players are currently in the game.

Convoy: In the building on the top right of the map, there's a cargo transport board showing the names of all the maps in the game, including the First Strike and Escalation packs.

There are "Wanted" posters all over the map of a boy named Raffaele Angelini at the age of 14. It says that he's wanted for "pwning noobs". It also says that his occupations are "Pwning noobs and being awesome" and that he's a very good Call of Duty player. Further down it says that he's very loved by the developers at Treyarch and Activision Blizzard. According to the description, he may be the son of one of the developers.

In the police station, posters can be found that says "Men with long hippie hair will be attended to last". Under it says that long hippie hair is: "Hair touching the eyebrows" or "Hair falling across the forehead" or "Hair covering the ears" or "Hair reaching below an ordinary shirt collar". There are also picture illustrating these.

In the lower left house there's a rack of magazines named "Exposed", which on the front page says "Russians launch first primate into space, and it returns a... WHAT THE HELL IS THIS?" with a picture of one of the Space Monkeys from Ascension on it.

In some buildings there are pictures of the maps Hotel and Stockpile.

Zombies
Note that the Zombies Mode easter eggs from World at War are also found in the Black Ops remakes.

Nacht Der Untoten

 * Undone (hidden song): Plays after shooting several barrels outside

Verruckt

 * Lullaby of a Deadman (Hidden song) Activated when one of the toilets are flushed 3 times

Shi no Numa

 * Radio: A radio which explains information about 115
 * Hidden Song- Talking on the telephone in the hut via Comm Room Section

Kino der Toten

 * 115 (hidden song): Plays a song when 3 pieces of meteor are activated.


 * Film Reels/Radios: 3 film reels can be found and played on the projector, and 3 radios (one of which has not been found) can be activated to play recorded messages.

"Five"

 * Telephones: Plays Eminem's "Won't Back Down" when all three red phones are activated.


 * Locations: 1st: Beside Quick Revive 2nd: Beside Juggernog 3rd: In Pack-A-Punch Room

Dead Ops Arcade

 * The hidden zombie game mode itself, Dead Ops Arcade, is unlocked by entering "DOA" in the CIA Data System.

Ascension

 * Kassimir Mechanism: Long easter egg requiring four players and Wonder Weapons; gives everyone a Death Machine for 90 seconds.


 * Abracadavre (hidden song). Plays after three teddies holding sickles are activated.


 * Character's dolls: Matryoshka dolls can be found that look like the original Nazi Zombies characters, which also talk.


 * There are several telephones across the map that will sometimes ring. When answered, character quotes from "Five" can be heard.

Call of the Dead

 * Original Characters Trapped: A long easter egg which sends the usual Zombies characters to "Paradise". Unlocks and achievement for performing this both in solo and multiplayer.


 * Not Ready to Die (hidden song): Hidden song by Avenged Sevenfold.


 * Radios: Play messages recorded by Richtofen.

Shangri-La

 * Eclipse: Another long easter egg in which you free Gary And Brock.


 * Pareidolia (hidden song): Plays a song when 3 pieces of meteor are activated.

Moon

 * Coming Home (hidden song): Plays a song when 3 Teddy Bears are activated.


 * Re-Damned: Hidden song which is activated by pressing the "use" button on a computer next to the Bio-Dome's door.


 * 8-bit Pareidolia: Hidden song which is activated by obtaining a disc and using it on a computer in the bottom floor of the labs.


 * 8-bit Coming Home: Hidden song which is activated by obtaining a disc and using it on a computer in Tunnel 6.


 * Nightmare (hidden song): Activated by having somebody die when an Excavator is down, and then finishing the round, resulting in them spawning on the other side.


 * Richtofen's Grand Scheme: A long easter egg which consists of two parts, which must be completed in the following order:


 * Cryogenic Slumber Party: An easter egg where it requires the player to complete a number of steps to release Sam from the Pyramid, when the pyramid opens, all players will be granted a Death Machine for 90 seconds.


 * Big Bang Theory: An easter egg which requires the players to complete a number of steps to launch three rockets to Earth. After they hit Earth, all players are granted with permanent eight perks.

Campaign

 * Snowman Room: Contains the Crossbow. Using it unlocks the weapon for multiplayer

Call of Duty: Modern Warfare 3

 * Teddy Bear: In the multiplayer map "Lockdown" there is a building not far outside the map on the right of 3 hanging bodies; the rightmost window on this building can be flown through if using a Recon Drone or if the player is in Spectator, inside is an over sized Teddy Bear wielding Akimbo Gold Desert Eagles that use the Call of Duty 4 model.
 * Lev Kravchenko: In the mission briefing for the level "Back on the Grid", a picture of Lev Kravchenko can be seen amongst the pictures of Markarov's associates.
 * Petrenko: On the mission "Turbulence", one of the soldiers helping the president's daughter is called Pvt Dimitri Petrenko. He can also be seen in Persona Non Grata as a Loyalist trying to help Soap
 * Arkaden Teddy Bear: In the map Arkaden, the food joint has a window the shows the "kitchen" it has many grills and a giant bear (much like the bear in lockdown but without the desert eagles).
 * Porter: In the map Mission, there is writing above a teddy bear saying: "Porter wuz here", which is a reference to the inventor of the Pack-a-Punched Ray Gun, from Zombies.
 * Wallstreet: In the Mission "Black Tuesday" when you reach the New York Stock Exchange there are TV-Screens on the Wall saying: IW, BLZ, SHG, WAR, ATVI and TREY these are References to Infinity Ward, Raven Software, Activision, Treyarch, Sledgehammer Games and Blizzard.
 * Train directions: When coming out of the tunnel with the wrecked train on Mind The Gap, there is a map of train directions with referencing names such as 'Black Cat Way', 'Verruckt', 'Infinity Station Ward', etc. And with weird names as well such as 'random place', 'no ammo road' etc. Also, this map is behind one of the original spawn points on Underground, the one that faces the actual subway station.
 * Gold Teeth: In the mission "Eye of the Storm", as you swim in a stream with Soap and Price, you will see the first dead body thrown into the water. Go to that body and as you pass through his body, stay in the middle of the figure as for a glitch will happen where you can see his eyes, teeth, and forehead. His teeth appears to have one gold tooth. His eye has a cut running from top to bottom. And his forehead has a scar that forms the initials "MW3". CAUTION: THIS ACTION WILL CAUSE THE RUSSIAN INFANTRY TO SEE YOU AND WILL SHOOT WITHOUT NOTICE. 
 * Carbon: On phones in this map, there is inscription - COD4
 * Shepherd: In the Special Ops mission Stay Sharp, after getting to Sandman, turn to your right without shooting any cutouts. You will see a picture of Shepherd with three throwing knives in it. One knife is in his eye; a reference to how you killed him in Modern Warfare 2.
 * Coca Cola: In Down The Rabbit Hole, after getting the intel, turn to your right. You will see a table with at 5 cans of Cola and one can on the ground.