[WARNING: This article contains spoilers for X-Men: Apocalypse]

There was a time when some fans might have thought that the days of the X-Men movie series had seen their best, but with X-Men: Apocalypse finally bringing the showdown between the mutant heroes and their greatest foe, Fox and director Bryan Singer clearly have more to give. And aside from mutant superpowers, world-ending carnage and hero-making battles, that means plenty of comic book easter eggs to enjoy as well.

Some may have been easy to spot, but require a deep understanding of the comic book history behind the "X-Men," "Wolverine," and even the animated series following the heroes and their villain onto the small screen. To make sure no nod, reference or easter egg would be missed, we've done our best to break them all down here (and keep adding as more are revealed).

Needless to say, there will be SPOILERS in our list of Every X-Men: Apocalypse Easter Egg & Secret Detail.

27. That Old Gag

20th century fox logo

Apocalypse keeps the trend alive for the opening title cards, as the 20th Century Fox logo goes through its usual show, but keeps the "x" lit for a moment longer on the fade to black (an easter egg created for the very first X-Men film from Bryan Singer). Not only that, but the classic music concludes with the patented X-Men musical sting.

26. Land of The Pharoahs

X-men Apocalypse Easter Egg Land Pharoahs

The movie in question might not be familiar to most audiences, but director Bryan Singer has confirmed that the opening scenes of Apocalypse - the ones set in ancient Egypt, and introducing Apocalypse and his Horseman - are heavily inspired by the classic Land of the Pharaohs (1955). It's reminiscent of one scene in particular, also set at the Great Pyramids of Egypt, with sliding stone blocks, collapsing structures -and more than one death.

25. Apocalypse's Transference

X-Men Apocalypse Easter Egg Power Comic

A quick look online might tell movie fans that swapping his consciousness from body to body isn't usually in Apocalypse's repertoire, but comic readers have seen something similar before. During the 1990s are "The Twelve" Apocalypse rounded up a dozen mutants to channel their powers into his new form - transferring his essence into the body of Nate Grey, since his former one had deteriorated. His body may not be so badly aged when he tried to do the same to Charles Xavier, but the same basic idea is at work.

24. The Celestials

Apocalypse and the Celestials - Facts You Should Know About Apocalypse

The cosmic side of the Marvel Universe may he kept to the fringes of the film, but it's obvious that the ancient Egyptian followers weren't the ones who cracked or created the technology that fuels the transference of Apocalypse from his old form to that of actor Oscar Isaac's character. From the first details of the film, comic fans saw the links between Apocalypse and the Celestials, the ancient alien  race whose technology helped the villain become even more powerful on the original comics. We'll have to see if such an answer is offered in future films (but fans shouldn't hold their breath, all the same).

23. The Blob

Xmen Apocalypse Easter Egg Blob

When Mystique first happens upon the mutants Angel and Nightcrawler, they're being forced to fight in an underground cage match. Angel is obviously the favorite, having dispatched over a dozen mutants forced to face him - the most recent being a massively obese man. In an X-Men story, that's almost always likely to be The Blob - the character previously seen fighting as part of Stryker's mutant strike team in X-Men Origins: Wolverine - and it's no different here. In fact, the character's costume from the comics is even carried over perfectly.

22. The Once & Future King

Xmen Apocalypse Easter Egg Once Future King

When we first meet Charles Xavier this time around, he's in the middle of class, reading a passage from T. H. White's "The Once and Future King" - a book that should be memorable for any fan of the films. Not only is Magneto seen reading it in The second of Bryan Singer's mutant blockbusters, but it's mentioned in another lesson by Xavier in the same movie. For those unfamiliar, the title hails from the (alleged) headstone marking the grave of King Arthur. In the comics, it's claimed to be Xavier's favorite books, although he has always viewed himself as Merlin, not Arthur (he trains and mentors the heroes). We can't help but think that Magneto would see his own quest for power reflected in the Star of the piece.

21. The Six Million Dollar Man

X-Men Apocalypse Easter Egg Six Million Dollar Man

Quicksilver returns to give not just one more superspeed  sequence, but plenty more pop culture references (even if he is still living in his mother's basement). Among them is his choice of shirt, sporting a nod to The Six Million Dollar Man of the classic TV show. It's not random, either: Bryan Singer is also a fan, since he was reported to be  developing a live-action film adaptation as recently as 2011 with Leonardo DiCaprio Rumored for the lead.

20. Who Mourns For Adonais?

Xmen Apocalypse Star Trek Easter Egg

When Apocalypse is ushered into Storm's home, he begins the (brief) process of learning what the world has become, including its many languages. He does it by pressing his hand to a TV set and tapping into the world's satellites - but pay attention to what's on the screen when he enters. It's another episode of the original Star Trek series (after one also appeared in Days of Future Past), this time, "Who Mourns For Adonais" follows yet another self-proclaimed god, referring to the crew of the Enterprise as "his beloved children." Who knows how much of an impersonation Apocalypse was doing for the rest of the film...

19. Storm, 'The Goddess'

Storm X-Men Comic Origin

Before Apocalypse begins to transform Storm from a street urchin to a white-haired Horseman, he refers to her as "goddess." It may play into the overall themes of godhood among mutants, but it's also a job to the comics, in which Storm really does end up worshipped as a weather goddess. As the latest in a long line of powerful mutants with mastery of the weather, Storm's ancestors were viewed as sorcerers in their African home.

18. Caliban, The Morlock

Xmen Apocalypse Easter Egg Caliban

He may not play the same role as he did in the original Apocalypse storyline of the comics, but the mutant Caliban makes an appearance all the same. Re-imagined here as as an information broker and document forger, the mutant Caliban actually adapts the visuals of the character faithfully. But the Morlocks to whom he belongs are nowhere to be seen (which may or may not be for the best).

17. 'The Third One's Always The Worst'

X-Men Last Stand Villains

When the young students waste their day at the mall, they're seen exiting a showing of Return of the Jedi, engaging in the debate right out of director Bryan Singer's own childhood. They continue the age-old weighing of the original trilogy, with Empire being the darkest, but owing its existence to the original. One thing they can all agree on: it's the third movie that's always the worst. If that isn't a dig at X-Men: The Last Stand, we don't know what is.

16. Jubilee's Style

X-Men: Apocalypse Mutant Power Rankings Jubilee

Every movie has some scenes that wind up on the cutting room floor - just ask Rogue. Unfortunately, the cutting job on this film all but removed the appearance of Jubilee, a fan-favorite of the team ever since she received a higher profile role on the animated series. Thankfully, for the little time she does appear, her wardrobe is almost a perfect match for her classic costume, starting with the incredibly-80s yellow jacket and hot pink accessories.

15. Angel's Anthem

Xmen Apocalypse Easter Egg Metallica Angel

When Apocalypse and his budding gang show up to recruit Angel, he's not exactly what they expected. Psylocke gets one look at the shirtless, drinking Angel in his shadowy loft and says they should leave, but before Angel is transformed, take note of the music he has blaring in the background. It's "The Four Horsemen" from Metallica's 1983 album "Kill 'Em All." Not only is it the right time period and tone, but the title makes it seem like fate, not just clever music.

14. Storm's Mohawk

Xmen Apocalypse Easter Egg Mohawk Storm

When Storm is transformed, Apocalypse shows that he also has a surprising interest in hairdressing. The shaved head and mohawk may be faithful to the comics but the transformation wasn't quite as "badass" to begin with. The style was changed due to Storm losing most of her hair, and the writers and artists deciding that no solution was going to please fans, so they might as well go to an extreme. That meant mohawk, and the leather jacket to match. Added bonus? The mohawk first appeared in 1983 - the year the movie is set.

13. The Fate of Family Magneto

Xmen Apocalypse Easter Egg Magneto Family

Audiences were shocked to see Magneto living without his powers, and starting a family of his own with a wife and daughter - but it too is taken from the comics. In the original version, Magneto found a wife in Magda who was as oblivious to his powers as the people who lived around them. Eventually an angry Mob showed up and, like in the movie, led to the death of his daughter (Anya, not Nina). In the comics Magda flees her inhuman husband, but in the movie winds up killed in the same scene.

12. A Lensherr Reaching

X-Men Easter Egg Young Erik Reaching

When Nina is trying to keep her father from being taken away, it's hard to miss the callbacks to the emergence of Magneto's own superpowers. For him, it was his parents being taken from him at the Auschwitz concentration camp (a scene shown in both the original X-Men and First Class). As he reached out to his parents, the powers arrived, bending metal fences. As Nina is pulled away by her mother, she reaches her hand out in the same way, for the same reasons - and her own powers answer the call just the same (with far more tragic an outcome).

11. 'You Have a Son?!'

Proteus Xmen

The shock that Charles shows when discovering that Moira Mctaggart was had s child since their time together may be played for laughs, but the fact that her son exists in the movies universe is far more important. In the comics, that son grew into Proteus, one of the X-Men's most powerful enemies. Could a similar plan be in place for the movies?

10. Stan Lee Cameo

Marvel icon Stan Lee

There no Marvel movie that doesn't feature a cameo from the Marvel legend Stan Lee, but in this film, the cameo is of a far grimmer tone. Lee appears as one of the many people watching as America's nuclear arsenal is sent into the sky. What makes this one special? Lee appears with his real-life wife, Joan.

9. Weapon X

Wolverine Weapon X Plus Marvel Comics

The movie made it close to release without the appearance of Wolverine being revealed, but the actual movie showed him in a truly new light. While invading Stryker's base, the young mutants stumbled upon the test subject deemed Weapon X. When he escapes, he appears complete with the headset and equipment  torn straight out of the comics, as drawn by artist Barry Windsor-Smith.

8. Director Cameo

Bryan Singer as Magneto X-Men

Bryan Singer has made a habit of finding cameos in recent X-Men films, and Apocalypse os no exception. But you'll have to look extra hard to make him out, since he appears in full costume as one of Stryker's armed guards - dispatched by a rampaging Weapon X a.k.a. Wolverine (Hugh Jackman). Luckily, he does stand out, since Singer appears as the guard firing a machine gun as the camera swoops past him, revealing only the blood splatter from his off-screen death.

7. The Phoenix Force

X-Men Apocalypse - Jean Grey as Phoenix

One of the worst kept secrets of the movie for any X-Men fan is the mysterious power growing inside of Jean Grey. She can't describe it, but comic readers know it's likely the cosmic Phoenix Force, an unparallelled source of power that, in the comics at least, led to a villainous turn for Jean (as Dark Phoenix). The story is being tweaked in this telling, removing the cosmic arrival of the force, but when Jean lets loose on Apocalypse the bird-like force emanating from her makes it obvious. It may be familiar to Apocalypse as well, since he witnesses Jean's strength and states that "all has been revealed."

6. 'I Feel a Great Swell of Pity...'

Patrick Stewart (Professor X) and Ian McKellen (Magneto) play chess in X-Men movie

Books are one thing, but director Bryan Singer found an even better way of linking his younger film series to the original. In the final scenes, Charles and Erik once again part ways, with the latter asking if the bald professor is ever awoken at night by nightmares, imagining a time when men will come to his school to take his children away. It's almost a perfect recreation of the scene concluding the first film, with Patrick Stewart and Ian McKellen sharing the same exchange, ending with Xavier's warning that "I feel a great swell of pity for the poor soul who comes to my school looking for trouble."

5. Familiar Wheelchair

Xmen Apocalypse Easter Egg Same Wheelchair

Words and haircuts aren't all that link the young Xavier to the older, either. When Charles arrives to bid farewell to Erik and witness his young pupils being trained by Mystique, he's sitting in a new wheelchair. Well, new to him - to audiences, it's the exact same wheelchair the original Xavier occupied in Singer's original films.

4. Classic Costumes

Tye Sheridan Cyclops New Costume X-Men Apocalypse

Bryan Singer claimed that this would be the true birth of the X-Men, and at least where costumes are concerned, it is. The final scene shows Nightcrawler donning his costume pulled straight from the origins comics, but it's Cyclops who gets the biggest moment. After seeing his yellow and blue costume and visor ignored in previous movies, this one goes back to basics, complete with the yellow straps added to his outlet by artist Jim Lee (which totally serve an important role in combat).

3. The Sentinels

Xmen Apocalypse Easter Egg Sentinels

What are the young mutants gathered to fight, and where? The location is an early version of the famous Danger Room, but it isn't complex holograms or virtual reality being used to train: it's a few confiscated Sentinels from the previous film that have obviously been modified to help the budding X-Men hire their skills.

2. X-23 in the Making?

X-23 Header

The obligatory post credits scene may actually be confusing or uneventful to those who don't see the story lines being referenced. Aside from cleaning up the facility of blood and bullet casings following Wolverines escape, mystery men arrive to take blood samples for unknown purposes. But remember that actor Hugh Jackman's time in the role is likely coming to an end, and the blood samples are probably a hint towards the creation of X-23, a young woman grown from the blood of Wolverine with his powers. Now that's one replacement in the movie universe that we can get behind.

1. Mister Sinister

Mr Sinister in Marvel Comics

The final easter  egg of the post credits sequence has to do with the name on the briefcase in which the blood sayers are stored: Essex Corp. As in Nathaniel Essex, better known to Marvel fans as Mister Sinister. The villain has a long history with the team and Apocalypse, even masquerading as the immortal mutant for a time. It's hard to guess where future films could put him to use, but it's a hint at what's coming, all the same.

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Those are the easter eggs, secrets and tiny touches we spotted in X-Men: Apocalypse, but be sure to let us know which ones we've overlooked, and we'll keep updating the list as more and more secrets are uncovered.

NEXT: X-Men: Apocalypse Post-Credits Scene Explained

X-Men: Apocalypse runs 144 minutes and is Rated PG-13 for sequences of violence, action and destruction, brief strong language and some suggestive images. Now playing in regular, 3D, and 3D IMAX theaters.