Call of Duty Zombieshas long been known for its easter eggs, from full stories hidden inside the original zombie maps inCall of Duty: World at WarandCall of Duty: Black Ops, to musical easter eggs and minor hints and nods to other games, both inside and outside theCall of Dutyfranchise.
InCall of Duty: Modern Warfare 3Zombies, players can find a canine companion to help them navigate the deployment area for a short time. In a small easter egg that nods toCall of Duty Black Ops: Cold War,players can find and befriend a hellhound, after which the hound will approach players and ask for some pets (as long as no nearby threats are present). If players can find where to summon a loyal friend, they can completeModern Warfare 3’ssecret achievement on Xbox and PC or trophy on PlayStation, You Can Pet The Dog.

Finding Chunks of Flesh and the Doghouse
While fighting through the horde, players will want tokeep their eye out for Chunks of Fleshthat drop from killed zombies. Players have a better chance of finding these fleshy bits whenkilling zombies in higher threat tiers and using explosive damageorupgraded weaponsthat causegibbing effectson the zombies. Trygrouping up zombies and running them into a claymore or dropping them with a gun modified with Shatter Blastto get zombies to drop Chunks of Flesh. Players canbring a Shatter Blast acquisitioninto the deployment with them to help find a chunk of flesh.
With the flesh in hand, begin prowling the map for aunique location called the Doghouse. The Doghouse will be indicated by a hellhound fact that appears to be in a classic, Snoopy-esque doghouse. Take the Chunks of Flush to the Doghouse andinteract with the flaming house to deposit the flesh.Once the flesh is deposited, a friendly hound will spawn, and begin patrolling the area, eviscerating any nearby mercenaries or zombies.

This hound is ruthless, and will oftentake off in search of attacking zombies that may not seem nearbyto players. Be sure tofollow the hound until he halts his chase. Once all nearby threats are eliminated, the hound will approach players, sit down, and wait patiently for more action. If playersapproach the hound and interact with it, they can give the hound some well deserved head patsbefore returning to the surrounding carnage. Players may remember petting the dog as a feature inCall of Duty Black Ops: Cold War, where players could interact with and pet a Brain Rotted hellhound or plaguehound, as long as there were no enemy threats nearby.
Once players pet the hound,the achievement or trophy will be awarded,and You Can Pet The Dog will be completed.