An Easter egg is an undocumented, obscure, or otherwise "hidden" command — usually buried deep within a program's source-code and only triggered by executing a certain series of actions or system commands. Often, an Easter egg will reveal an inside joke, though Easter eggs can also be placed into in-game props and scenery or only in areas visible to those that are actively using "cheat codes" (or otherwise circumventing the "normal" operation of the software).
While Easter eggs were once included in virtually all computer software, software companies such as Microsoft have discontinued the practice, citing security concerns associated with undocumented (and often untested) code.
For more hidden in-jokes and references, see in-jokes and references.
Easter eggs in-game
These are mostly Blizzard-related Easter eggs.
See In-jokes and references for more.
Guards of cities will respond to some emotes such as /wave, /rude, /kiss,/chicken,/shy, or /salute. This does not apply to all guards though, most notably Darnassus Sentinels do not reply to emotes and even the same guard will not always respond. However, if you ask a Darnassus Sentinel about the enchanting trainer, she may respond as if you said she was enchanting. Also, if a blood elf paladin /eye a Silvermoon Guard, they will /kneel.
Goblin Shredder display
At the Shrine of the Fallen Warrior, there is a memorial dedicated to an orc with the initials "M-K". M K was Michel Koiter, one half of Twincruiser, a Blizzard illustrator who passed away during the development of World of Warcraft. If you visit the memorial, you will find a spirit healer named Koiter. Most likely named in dedication for the once beloved man.
Players who are fed up with the rude female dwarf who presides over the quest chain to obtain the key to Searing Gorge, Mountaineer Pebblebitty in extreme southern Loch Modan, may feel inclined to use /rude on her after all the trouble she puts them through. Blizzard has anticipated this and provided an appropriate response.
Deeprun Tram sightings
If you own a non-combat pet and stop moving for a while, it will begin to sleep or do other kinds of emotes.
- The Zergling pet will chomp at air.
- The Murky pet will sing and dance.
- The Mini-Diablo pet spouts out fire when he is idle.
- The Panda Cub and Sleepy Willy lie down and sleep (you see green Z Z Z ...) when idle.
- The Speedy pet will shout, scaring nearby critters.
- The Peanut pet will occasionally blow his nose, making a noticeable elephant noise.
- The Willy pet will occasionally kill nearby critters with an eye-beam.
- The Egbert pet will run around like a caffeinated two year old.
- The Pandaren Monk pet will respond to /bow and /drink emotes. Also, he will do... kung fu!
- The Core Hound Pup pet will howl, stand on its hind legs and bark, roll around, and dig up a bone.
- The Onyxian Whelpling pet will emote a deep breath, but fail and let out a plume of smoke.
- The Grunty pet will start to shoot his gun. If a Zergling pet is nearby, the two will battle until one pet dies (gets despawned).
- The Tyrael's Hilt summons Tyrael from the Diablo games. He responds to /dance emotes, and will sleep while floating in the air.
- The Perky Pug pet will occasionally drag his rear along the ground.
- The Stinker pet will chase any nearby Bombay Cat, Black Tabby, or Feline Familiar pets and gain a heart above his head, before it breaks. The reference is from Pepé Le Pew.
- The Lil' Phylactery pet will occasionally Frost Block a nearby critter, killing it.
- The Toxic Wasteling pet will occasionally devour critters (and grows in size by doing so) if you bring it close to them.
- The Creepy Crate pet will occasionally deathgrip critters and devour them, burping out a green gas and "licking its lips" afterwards.
Stratholme Spectral Citizens
If you type /dance on the civilian ghosts in Stratholme, they will respond in kind and dance with you. Even if you attack them, subsequently dancing with them will make them dance with you instead of continuing to attack you.
Also, appropriately, they will respond to the /rude emote with a rude action of their own.
Hidden Mickey Mouse
An exceptionally well hidden Mickey Mouse is located in the Valley of Honor within the Horde city of Orgrimmar, where the Hunter trainers are. It is so large, and so well sculpted into the surroundings, that most people will never know that it is there. The only way to see it is to manually increase the maximum zoom setting of the camera.
The punch cards you get in gnomeregan all have hidden binary messages on them which can be translated easily from screenshots with an online translator. I have them all here.
Bambina (Bambi), Mother of Bambina (Bambi's Unnamed Mother), Flora (Flower), and Thudder (Thumper) will all be walking in close proximity to the Westfall Brigade Encampment where the ground is yellow (You will know what I mean when you get there). Also, there is a mob named "Westfall Brigade Hunter" who will occasionally spawn and shoot Mother of Bambina and do a /cheer, causing Bambina to become enraged, get renamed to "Vengeful Bambina", and start attacking the Hunter.
The Lost Vikings
Go into Uldaman and find the 3 Dwarves. Olaf, Eric "The Swift", and Baelog are all lost inside Uldaman. Those 3 Dwarves are all from another game named The Lost Vikings. The staff and medallion are also references. The "Staff of Tsol" and the "Medallion of Gni'kiv" are used for another quest. "Tsol" and "Gni'kiv" are "Lost" and "Viking" backwards.
Along the Webwinder Path, there are some felled trees. One end has a large smilie face on it.
JasonIn Elwynn Forest "Crystal Lake" is a reference to "Friday the 13th". You can also find "Jason Mathers" at the dock next to the fishing trainer.
There is also a large smiley face underneath Karazhan. You can see it if you log out near Karazhan. Once you log back in, before the doodads and NPCs load up, you can see the smiley face. Humans can get under Karazhan to the smilie face by jumping to a certain ditch in the corner of the rubble in the back side of Karazhan (facing the crypt/graveyard).
When floating underwater, one of the motes that float by will very occasionally be a tiny smiley face.
If one zooms in to the top of a Restoration Druid in Tree of Life form, he can see a hidden smiley face on the bark.
In the Allen Farmstead in Gilneas there is a painting of a girl, look closely and you'll notice she opens and closes her eyes.
On any Icebreaker ship, there is a smiley face inside at the front.
There is a small island in the Bittertide Lake in Sholazar Basin with a door and a handle, on which there is a plaque that reads "5 9 16 17 24 43". It's a reference to the sequence of numbers "4 8 15 16 23 42" from the show Lost.
Northeast of Thunder Bluff on top of a mountain is a line of text that reads "HERB", but at another look you will see that it says "HELP" backwards.
Just Southeast of Hammerfall at the right angle, you can clearly see "LOL" carved into the mountain-side.
In the Quest Blindeye the Guardian you kill an ettin named blindeye the guardian this could easily be refering to the band blind guardian also if you fly above the building he is in it makes a guitar.
Big Papa and Alice
At Windshear Hold in the Stonetalon Mountains there is an elite gnome mech called Big Papa, a little girl is seen walking around the massive machine occasionally saying "Wake up Mr. P" or "Wake up Mr. P! You've gotta save the spirts." This is a reference to the Big Daddy and Little Sister characters from 2k's game Bioshock.
In the same area there is also a citizen form Gilneas who says a modified version of the speech given by Andrew Ryan, the main villian from the first Bioshock game
In Mists of Panderia in the Valley of the Four Winds by the Imperial Grainery that is plagued by Sprites, Under the Archway to the main building, there is a squash with a pilgrim hat on it hidden is sitting there waiting. This may be a reference to the first American thanksgiving, in which the pilgrims had little to drink but Beer due to the poor quality of the water.