Easter eggs
The Assassin's Creed series contains some easter eggs inside its games, and many other games had Easter Eggs related to Assassin's Creed within them, such as Metal Gear Solid 4, Grand Theft Auto IV and the 2008 version of Prince of Persia. This page lists them.
Assassin's Creed
Transformers
An arrangement of windows on certain buildings form the face of Optimus Prime in truck mode from the Transformers franchise.[1]
Jamal
Upon leaving Masyaf for the first time, one of the Assassins in the Kingdom is marked as an enemy (glowing red when seen through Eagle Vision). He can be silently assassinated with no consequences, but openly attacking him will prompt the other Assassins to attack you.
This Assassin is actually Jamal, the traitor inside the order that, along with Masun, opened the gates for the Templar attack at Masyaf. He was originally set to be a mission target to be assassinated, but the mission was cut, and the character remained as a minor Easter Egg.
Assassin's Creed II
Mario
300px|right At the beginning of the third sequence, Ezio's Uncle says "It's-a-me! Mario!" which is a reference to Super Mario Bros. To further support this is Mario Auditore's Italian nationality, like Mario of Super Mario Bros.
Giant Octopus

A giant octopus can be found in the Assassin's Tomb of Santa Maria Della Visitazione. The octopus appears before and after activating the lever that brings out the bars used to traverse the final chamber.
To find the giant octopus, you must look down into the water near the lever for one minute. Once a minute or so has passed, a cutscene plays, showing a large octopus swimming by. A second cutscene can be activated if the player pulls the lever and looks down again. The cutscene shows Ezio narrowly dodging the octopus's tentacle, before it swims away.
Altaïr's Outfit
right|thumb|300px Altaïr's outfit from Assassin's Creed can be unlocked via Uplay by purchasing it for 30 points. It does not add or change any stat points for Ezio. It can also be worn in conjunction with any cape, allowing the player to wear the Altaïr outfit and still maintain 0% notoriety with the Medici or Venetian Capes. A glitch here is that, when used with the double blades, Ezio makes the movement with his right hand though no blade appears. The same glitch is present in Assassin's Creed Brotherhood with outfits such as Altaïr's Robes, Desmond, Raiden and Florentine Noble Attire (last of which has no hidden blade on either wrist).
Ghosts of the Past
thumb|300px|left After downloading the Bonfire of the Vanities DLC, Ezio is briefly able to see a vision of his whole family. After meeting up with Niccolò Machiavelli, return to Palazzo Auditore and step into the center of the courtyard. Ezio will enter a mode similar to his Eagle Vision, and be able to see the figures of his parents and all of his siblings around the palazzo. Once you leave, the vision will disappear and you will not be able to see it again. (The vision cannot be viewed if you have completed Bonfire of the Vanities, so make sure to do this beforehand).
Palazzo Ducale
thumb|300px|right|Palazzo Ducale Easter Egg After using the Super Jump or Fence glitch to get into the Palazzo Ducale, you can access the Doge's quarters where Carlos Grimaldi assassinated the Doge. The candle that Carlos Grimaldi and the Doge were playing under is unlit, but the chess pieces are in the exact same position, though Ezio assassinated Grimaldi, years ago (this is most likely an oversight). After you go into these quarters the sky and the building turn a blood red.
However, this may not be intentional, but accidental, as scenery when entering other buildings such as the Auditore Villa lighten or darken to match the interior of that building. In this case, the tone is changed to orange or red to match the interior of this specific room, thus changing the outside scenery and sky to orange and red respectively.
Dummy Keys
In the mission "Knowledge Is Power", the player may loot the dummy target and find keys. The keys have no effect whatsoever in the game.
Batman
Occasionally, while freerunning or climbing a building, a male bystander can be heard saying "Another capering crusader.", a reference to the DC Comics superhero Batman who uses stealth and has a tendency to run on rooftops. Batman is sometimes referred to as the Caped Crusader.
Assassin's Creed: Brotherhood
The Hunchback of Notre Dame
One of the achievements/trophies is titled "Sanctuary! Sanctuary!" The same words were shouted by Quasimodo when he carried Esmeralda into the cathedral under the law of sanctuary in order to prevent her execution.
Project Legacy
In the Sanctuary, if you look at one of Lucy's Monitors, you see the Memories menu of Assassin's Creed: Project Legacy.
Castle Crashers
The first memory in the Castel Sant'Angelo is called Castello Crasher. When the word Castello is translated into English, we get the title Castle Crashers, which is close to the PS3 and Xbox 360 downloadable game, Castle Crashers.
Solid Snake
Just before meeting Leonardo da Vinci for the first time in the game, Ezio will come across a factory-made cardboard box that is completely unsuitable for the era; though he looks away when Leonardo comes around the corner. This is a reference to the Metal Gear Solid series, as Solid Snake's (the series' protagonist) signature stealth move is to hide in a box or crate.
Raiden
A second Metal Gear Solid tribute is the Raiden suit, available to all who complete every challenge in the Animus Virtual Training Program with at least a bronze medal.
Mario References
One of the achievements/trophies in Assassins Creed: Brotherhood is titled "Principessa in Another Castello." This translates to Princess in Another Castle, which is what would be told to Mario in the original Mario games when he defeated Bowser's minions in their castles.
Another Mario reference is the Plumber achievement, which shows the picture of a Warp Pipe.
Montreal
During one of the memories in Sequence 6, whilst escorting Bartolomeo d'Alviano and his Mercenaries disguised as French soldiers, a French guard asks Ezio Auditore which region of France he hails from, to which he replies "Montreal." This is likely a reference to Ubisoft Montreal, the main developers of the Assassin's Creed series. Alternatively, it could be a reference to the birth-place of Francisco Randez - the character model after whom Desmond Miles was designed.
It should be noted that Ubisoft Montréal is located in Montreal, a city in Canada (province of Québec), not France. However, there is also a small village in France, called Montréal, that existed before Jacques Cartier found the island on which Montréal lies today.
Machiavelli's Works
Shortly after Ezio successfully enlisted the help of the three other guilds, Machiavelli asked Ezio how he had managed it. Ezio simply answered that it was "Virtù," a concept about the spirit of leadership that Machiavelli was later known to have theorized.
Additionally, at the end of Sequence 7, Machiavelli stated that "I intend to write a book about you one day" to Ezio, who then responded with "If you do, make it short." This is clearly a reference to Machiavelli's notoriously short book, "The Prince."
Assassin's Creed in other media
The stories and characters of Assassin's Creed are not only featured in the official video games, but in other media as well.
Grand Theft Auto IV
After completing a set of assassination missions for a mysterious figure called the Fixer, the player will receive an Achievement/Trophy called Assassin's Greed which is a direct play on the Assassin's Creed name. Moreover, the requirement for the Achievement/Trophy is the completion of 9 assassination missions, which parallels the first Assassin's Creed game, in which Altair was tasked by Al Mualim to kill 9 men in exchange for his reinstatement as a Master Assassin.
LittleBig Planet
As a part of their promotion for Assassin's Creed II, Ubisoft released a downloadable costume for the PS3 exclusive LittleBig Planet, Ezio's "Purple Assassin" Costume on December 8, 2009.
Metal Gear Solid 4
On April Fools' Day 2008, it was revealed that an Altaïr costume for Old Snake could be unlocked in the game Metal Gear Solid 4. Hideo Kojima (from Konami, the creators of Metal Gear Solid 4) later announced that this was no joke, and that the costume would really be unlocked if the player did "something special." In order to unlock the costume, the player must either acquire the "Assassin Emblem" (a nod to the game's title), or input a password in the Extras section.
The costume can be used as an alternative disguise early in-game, and can keep the player from gaining any unwanted attention. When the costume is put on, the protagonist will bend his ring finger back to his palm, which is maintained so long as Snake wears the costume. This is a nod to Altaïr's missing ring finger.
The password has been revealed to be aottrykmyn[2]
Prince of Persia

In Prince of Persia (2008), Altaïr's costume is available as a free DLC for use by The Prince. Additionally, an achievement entitled "Assassin's View" can be unlocked by standing on a View Point upon the Martyr's Tower.
Similarly, in Prince of Persia: The Forgotten Sands, Ezio's costume can be purchased via Uplay for 30 points.
The Saboteur (2009)
The main protagonist Sean Delvin earns a red racing car with white stripes named Altaïr, which is nicknamed "The Flying Eagle."
Naruto: The Broken Bond
Completing all the bounty hunter missions in the game will award you with the achievement "Naruto's Creed."
Metal Gear Solid Peace Walker

- "Back in the time of the Crusades, members of the order of Assassins used what is called the Assassin's Straw Box to hide and get close to their enemies."
- ―Kazuhira Miller, commenting on the player's newly procured item.[src]
In one of the game's missions (namely Main Ops 16) a unique box made of straw dubbed the Assassin's Straw Box can be obtained. To do so, the player must ensure there's a vacant slot in the equipment section, climb onto the roof of the shack above where the straw box is, then perform a "leap of faith" into it. The "leap of faith" is then accompanied by an eagle's screech, similar to its mechanism in the Assassin's Creed series.
Right after you obtained the straw box, one of the main protagonists, Kazuhira Miller, will mention its use during the Third Crusade (the time period of Assassin's Creed) and how it was used by the Assassins. The box can hold two people simultaneously and allow a special function which other box items don't have, which is knocking out guards while hiding in the box (and if another player is present, recruit the knocked-out soldier using Fulton Recovery). Continued use can damage the item, to the point where the box will be destroyed completely.
After the aforementioned mission is completed, the Assassin's Straw Box will be available in the inventory.
AdventureQuest Worlds
In AdventureQuest Worlds, go to Yulger at the inn, and look into his suggestion shop. There will be two outfits called "Hashashin Armor" on sale for 500,000 gold for free players, and the "Armored Hashashin Armor" for 300,000 gold for upgraded players, both designed and created by a member named "Rohan." The Hashashin Armor includes two hidden blades, though located on top of the player's wrist, rather than on the bottom.
Killzone 3
In the Killzone 3 story trailer, an enemy was revealed to use a weapon similar to the hidden blade, with which they executed an air assassination.
Dragon Age 2
Varric's crossbow is called Bianca, like Bartolomeo d'Alviano's sword.
References