Like every good comic book movie, X-Men: Apocalypse is filled with tons of Easter eggs and cameos for comic book fans to discover and appreciate. Not only does Apocalypse have call backs to the comics, it also references several past X-Men films, particularly the ones directed by Bryan Singer over a decade ago. So without further ado, here is every cameo and Easter egg we found in X-Men: Apocalypse:
During Angel's introductory scene, he's shown fighting the Blob, a classic X-Men villain. While he's never named, the Blob is even wearing his classic costume from the comic down to the yellow trim. Although his powers aren't really shown, the Blob is virtually indestructible and can render himself immovable whenever he wants. The Blob previously appeared in X-Men: Origins: Wolverine as a member of Team X who became morbidly obese after the team disbanded.
The Once and Future King
When Xavier first appears in X-Men: Apocalypse, he's shown reading from a copy of The Once and Future King by T.H. White. Singer referenced The Once and Future King several times in X2. Not only does the end of the movie show Xavier teaching from the book, Magneto is also a fan of the King Arthur story as he reads the novel while in prison.
Scott Summers' high school teacher is played by Ally Sheedy, best known for her roles in various teen movies. Her best known movie was The Breakfast Club, a 1980s' classic about a group of outcasts who bond during a weekend detention. Although joining the X-Men is hardly the same as detention, there's still probably a parallel between Scott and the other mutants and the angry, confused teens shown in The Breakfast Club.
Apocalypse refers to Storm as a goddess, a reference to one of her many titles in the comics. When Storm first appears in the comics, she is worshipped as an actual weather goddess by several tribes in the Serengeti plains of Africa. Although Storm learns from Xavier that she's not really a goddess, other characters' occasionally refer to her as a god due to her powerful weather abilities.
Caliban, a mutant who has a history with both the X-Men and Apocalypse, makes a cameo appearance as a black market broker working in Eastern Europe. In the comics, Caliban has the ability to track other mutants. While Caliban is originally a scrawny, deformed Morlock living under New York, Apocalypse recruits the mutant and transforms him into one of his Horsemen. Caliban later reforms and becomes a useful ally to the X-Men.
The Third One's the Worst
One of the more obvious meta-jokes, Jean Grey comments that the third movie is "always the worst" upon exiting a screening of Return of the Jedi. That's a pretty obvious dig at X-Men: The Last Stand, the derided third X-Men movie that nearly put the entire X-Men franchise on hiatus. Of course, that could also be a joke about X-Men: Apocalypse, as it's the third movie in the First Class trilogy.
The Four Horsemen
When Apocalypse and the others come to recruit Angel to their side, he's drinking and listening to Metallica's "Four Horsemen", a song from their debut album "Kill 'em All". That's a clever nod to Apocalypse's four horsemen (who are explicitly named as such several times in the movie.)
Storm's transformation into one of Apocalypse's Horsemen comes with a radical haircut that probably reminds comic readers of Storm's haircut in the 1980s. After having long white hair during the 1970s, Storm ditched her traditional look for a mohawk and a new punk outfit. Although Storm later regrew her hair, she's returned to the mohawk several times, most recently during the current run of X-Men comics.
Stan and Joan Lee
Stan Lee makes his usual cameo appearance in X-Men: Apocalypse as one of the many people watching the United States' nuclear payload unleashed into the atmosphere. Interestingly, he appears alongside his wife Joan, who previously voiced Madame Web in the 1990s Spider-Man cartoon.
Moira mentions she has a son to Xavier, who is somewhat surprised by that news given their romantic past. In the comics, Moira's son becomes the superpowered mutant Proteus, who has the ability to reshape reality. Proteus became a dangerous adversary of the X-Men, as he attempted to transfer his psyche into Jean Grey's in order to use her Phoenix abilities to halt his powers from consuming his body entirely. Colossus later kills Proteus, as his one weakness is metal.
Scott, Jean and Kurt rescue the rest of the X-Men from the Weapon X facility with the help of a feral Wolverine. Wolverine's helmeted outfit is almost identical to his look in several comics dedicated to Wolverine's time in the Weapon X program, when the Canadian government brainwashed him and stripped him of his memories.
The Phoenix Force
The X-Men defeat Apocalypse after Jean Grey taps into the Phoenix Force and uses it to totally disintegrate Apocalypse's body. The Phoenix Force even briefly appears in its usual fiery form surrounding Jean as she fights Apocalypse. In the comics, the Phoenix Force is a cosmic entity who merges with Jean Grey after she nearly dies piloting a spaceship back to Earth. The Phoenix Force is eventually corrupted and becomes evil, leading to Jean's death. The Phoenix Force has returned to Earth several times, most recently in Avengers Vs. X-Men, when it saved the mutant race from extinction and corrupted Cyclops and several other X-Men.
Charles and Eric's Parting Words
Charles and Eric's parting words to one another in X-Men: Apocalypse is a word for word rehash of a conversation between the pair in the first X-Men movie. While Charles and Eric part as friends in Apocalypse, their conversation in the original X-Men movie takes place while Charles visits Eric in prison.
At the end of the movie, Xavier uses a wheelchair identical to his wheelchair used in the first X-Men movie. Glad to see 20th Century Fox kept the wheelchair after all these years.
The X-Men fight several repurposed Sentinels in the Danger Room while training at the end of the film. Not only is this a callback to X-Men: Days of Future Past, it's also a reference to X-Men: The Last Stand, when Wolverine, Colossus and several other X-Men fight a Sentinel offscreen in the Danger Room.
Mister Sinister and Cloning
The end credits contain two big easter eggs, both of which relate to a classic X-Men villain. Workers from "Essex Corp." collect several blood samples from the Weapon X facility, including blood from Wolverine. Essex is the real name of Mister Sinister, a mutant scientist obsessed with cloning and genetics. The blood sample is a probably a hint at X-23, a female clone of Wolverine created by the Weapon Plus programming. X-23 recently took up Wolverine's name and mantle after Wolverine's recently died in the comics.