MASSIVE SPOILER WARNING: This article contains comprehensive spoilers for "Logan," in theaters now.

In James Mangold's "Logan," audiences finally got to see the full fury of Hugh Jackman's Wolverine unleashed. With Patrick Stewart's weary Charles Xavier and Dafne Keen's feral Laura/X-23, Logan's last adventure sent one era of X-Men movies out on a high note while laying groundwork for a new age. While the film's bloody action and strong characters made it a rewarding standalone experience, it's still very much a part of Fox's wider X-Men Cinematic Universe.

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Now, CBR is taking a look at the best obscure references, Easter Eggs and hidden connections in "Logan." For this list, we'll be looking at examples from the movie that draw from the rich comic and cinematic history of Wolverine and the rest of Marvel's uncanny mutants.

16 THE DEADPOOL TEASER

Deadpool-fireplace

One of "Logan's" biggest surprises arrived before the feature even started. In an unannounced teaser for "Deadpool 2," Ryan Reynolds' Wade Wilson changes into his Deadpool costume in a phone booth, but is too slow to save a passerby from being mugged and shot. This whole sequence references Clark Kent's famous quick-change into his Superman outfit while in a phone booth, which is highlighted by the notes of John Williams' iconic score for 1978's "Superman: The Motion Picture."

During the three-minute short, Deadpool also muses on Logan's penchant for saving the day in jeans and a tank top. In the version released online, Stan Lee makes an obligatory cameo before being told off by Deadpool. There are also several posters for the Fox-produced sci-fi series "Firefly," which starred "Deadpool's" Morena Baccarin and ran for one beloved season in 2002. Some graffiti on the phone booth also states that "Nathan Summers is coming!" That mentions Cable's real name and doubles down on "Deadpool's" post-credits promise of an incoming live-action Cable. Although there hasn't been any official Cable casting news yet, recent reports have indicated that "Stranger Things" star David Harbour may be up for the role.

15 CALIBAN

Logan caliban

In "Logan," Stephen Merchant's mutant-tracker Caliban helps Wolverine look after Professor X. While he serves as a concerned caretaker here, he was a less charitable figure in 2016's "X-Men: Apocalypse." In that 1980s period adventure, Tómas Lemarquis' Caliban acts as a mutant trafficker and information broker. Although that Caliban is a mercenary figure who refers to himself in the third person, Merchant's Caliban is more defined by his aversion to sunlight and his intelligence.

Although those two takes on Caliban seem pretty far apart, they fit the character's comic book arc. Caliban made his debut as a sewer-dwelling Morlock in 1981's "Uncanny X-Men" # 148, by Chris Claremont and Dave Cockrum. After dozens of Morlocks died in the Mutant Massacre, he joined the heroic mutant team X-Factor. In order to gain enough power to seek revenge on the Morlocks' killers, Caliban voluntarily joined Apocalypse. After receiving a monstrous physique and working with Apocalypse for years, he eventually defected to Cable's X-Force. Although he briefly served Apocalypse again, he died saving the X-Man Warpath in 2008.

14 X-MEN COMIC BOOKS

Logan wolverine comic book

In one of "Logan's" lighter moments, Logan criticizes two X-Men comics that Laura has in her backpack. When this scene dropped in a trailer, Marvel CCO Joe Quesada wrote about how he and Dan Panosian created the comics' retro-looking artwork. Both of those "Uncanny X-Men" issues are published by the "X-Men Comics Group" and feature logos that look like Marvel's mid-1970s trade dress. One of those issues features the longtime X-Men villain Sauron, an energy vampire who looks like a dinosaur. The other, "Uncanny X-Men" #132, references a real 1980 issue that ends with one of the most famous moments in Wolverine's comic book history.

While the "Marvels Comics" event gave readers another look at comic books from the Marvel Universe in 2000, this scene shows how famous the X-Men are in their cinematic world. At one time, the X-Men were popular enough to star as brightly-clad superheroes in their own comic series that ran for at least 132 issues. Wolverine was even popular enough to merit an action figure, which is seen later in the film. Appropriately, this toy clearly shows Wolverine in modern yellow costume, which Laura currently wears in "All-New Wolverine."

13 THE REAVERS

logan reavers

In the real world, Chris Claremont and John Byrne's "Uncanny X-Men" #132 showed how Donald Pierce and the rest of the Hellfire Club made quick work of the X-Men. On the last page of that comic, an angry, battle-weary Wolverine promises to take his revenge. And in "Uncanny X-Men" #133, that's exactly what he does by severely wounding and dismembering several of the club's human guards. Years later, some of those injured guards received cybernetic upgrades from Pierce and sought revenge on the X-Men as the Reavers.

Although Boyd Holbrook's Donald Pierce still leads the Reavers in "Logan," he doesn't seem to have any connection to the Hellfire Club from 2011's "X-Men: First Class." Macon, Pretty Boy and Bonebreaker, some of the Reavers' more recognizable members, all appear in "Logan," but they lack their more extravagant cybernetic features. In a possible nod to the cyber-squad's comic book origins, Wolverine and Laura dismember, decapitate or otherwise murder most of the Reavers by the film's end.

12 MUTANT CURE

x-men last stand dr kavita rao

To put it mildly, 2006's "X-Men: The Last Stand" is a controversial film. Despite a few genuinely good ideas, its major deviations from X-Men lore helped trap the franchise in a place where it couldn't go forward without major changes. In a loose adaption of part of Joss Whedon and John Cassaday's "Astonishing X-Men" run, one of that film's main sub-plots revolves around a mutant cure, developed by Shohreh Aghdashloo's Dr. Kavita Rao.

Although the time-travel shenanigans of 2014's "X-Men: Days of Future Past" reset the franchise's continuity, a similar mutant cure helped shape the world of "Logan." As Richard E. Grant's villain Dr. Zander Rice states, a mutant cure was mixed in with genetically-modified corn syrup that was widely consumed in a variety of products. In echoes of the 2005 storyline "Decimation," this saw the number of new mutants fall dramatically. After that era of X-Men comics, the appearance of a new mutant, Hope Summers, helped shaped years of stories throughout the X-Men titles. Similarly, the discovery of Laura and her fellow test subjects drives most of the action in "Logan."

11 LOGAN'S KATANA

Wolverine sword

Wolverine's connections to Japan have been one of the character's defining traits for most of the character's existence. Even late in his superhero career, his meaningful experiences in Japan helped him shape his code of honor and conquer his inner demons over the course of his century-long life. James Mangold's "The Wolverine" finally brought one of Wolverine's Japanese adventures to the big screen in 2013.

In Mangold's "Logan," Wolverine has a katana clearly displayed on the sparsely decorated wall of his bedroom. While this is a regular feature in most of Logan's comic book living quarters, it holds a deeper meaning for the X-Men Cinematic Universe. Since "X-Men: Days of Future Past" reset the franchise's continuity, "The Wolverine" takes place in a timeline that never happened. Despite that, the sword's presence suggests that "Logan's" Wolverine still has some sort of relationship to Japan in the revised timeline. Even though "The Wolverine" isn't in continuity anymore, the blade is a nice nod to Logan's cinematic and comic book history.

10 ADAMANTIUM POISONING

Wolverine claws poison

While Wolverine's adamantium claws are some of his most defining features, they've been slowly poisoning Wolverine for decades. Although Logan's claws are a naturally occurring part of his body, Wolverine's skeleton was coated in the unbreakable metal adamantium in the Weapon X Program. Thanks to his powerful mutant healing factor, Wolverine was able to survive the adamantium-bonding procedure and constantly recover from the metal's adverse effects on his body.

In "Logan," Wolverine's failing healing factor leaves him vulnerable to adamantium poisoning. Whenever Logan's lost his powers in stories like Paul Cornell and Alan Davis' 2013 tale "Killable," he's suffered from the metal's long-term health effects in comics too. Due to his exposure to nuclear blasts, like the one in "The Wolverine," and other exotic forms of energy in his adventures, a depowered Logan has also been diagnosed for some radiation-based diseases. During these weakened eras, Wolverine has risked life-threatening infections from the bacteria drawn into his bloodstream whenever he pops his claws.

9 DR. ZANDER RICE

X-23 vs Zander Rice

Although he's not as famous as some of Marvel's other mad scientists, Dr. Zander Rice has a history of torture in the Marvel Universe. Like Richard E. Grant's "Logan" villain, Rice's father was a scientist at the Weapon X Program and was killed by Wolverine in a berserker rage. As revealed in the 2005 miniseries "X-23," by Christopher Yost, Craig Kyle and Billy Tan, he carried on his father's work for the Facility and helped lead the program that created X-23, Wolverine's artificially-cloned surrogate daughter Laura.

Although the corporation Alkali Transigen only appears in the film, Rice cruelty remains consistent across mediums. In comics, he conducted brutal experiments on Laura and gave her a trigger scent, a smell that turned her into a mindless killing machine. After showing her several other embryonic clones including X-24, Rice was killed by X-23. In a final act of savagery, Rice used the trigger scent to trick Laura into killing her surrogate mother, Sarah Kinney.

8 GENETIC WEAPONS

logan x-23 laura

In "Logan," Laura and Transigen's other test subjects were created with powers seemingly derived from other mutants' DNA. Both Laura and X-24, the savage Wolverine clone, were likely engineered from the sample of Wolverine's DNA that was recovered in "X-Men: Apocalypse's" post-credits sequence. Although several of the young test subjects have powers that look familiar, one child has electricity powers seemingly derived from Christopher Bradley, a mutant played by Dominic Monaghan 2009's "X-Men Origins: Wolverine."

The idea of using samples from real mutants to create super-powered weapons has popped up in two other X-Men movies. In the 2009 film, Ryan Reynolds' mouthless Deadpool infamously possessed Cyclops' optic blasts and John Wraith's teleportation abilities. In the dark future of "X-Men: Days of Future Past," the robotic Sentinels have highly-adaptive technology that can replicate a wide range of mutant powers. As Jennifer Lawrence's Mystique discovers, those powers are based on samples taken from several dead mutants, including Banshee and Angel Salvadore.

7 WOLVERINE'S DOUBLE

Wolverine robot albert

After decades of secret government programs and genetics-focused storylines, the X-Men might have more clones than any other major superhero franchise. In "Logan," this time-honored trope finally leaps to the big screen with Hugh Jackman's ruthless Wolverine clone X-24. Visually, the clone references Liev Schreiber's Sabretooth from "X-Men Origins: Wolverine" and the dark, sleeveless uniform Wolverine wore sometimes in the 1980s. Although he's not in this film, its seems likely that the genetics-obsessed villain Mr. Sinister had a role in the clone's creation, since his Essex Corporation took control of Wolverine's blood samples in "X-Men: Apocalypse."

Although Donald Pierce didn't have a hand in X-24's creation, his comic book counterpart created another Wolverine double in 1991. In Larry Hama and Marc Silvestri's "Wolverine" #38, Pierce created a robotic Wolverine doppelganger in order to lure the real Wolverine into a trap. While Wolverine investigated his double, Pierce planned to detonate a bomb hidden inside the robotic girl called Elsie Dee. After the two androids were able to eventually override their programming, the Wolverine robot took the name Albert and the pair became Logan's infrequently-appearing allies.

6 PROFESSOR X'S SEIZURES

Logan professor x

In the dark future of 2008's "Old Man Logan," by Mark Millar and Steve McNiven, Wolverine was tricked into slaughtering most of the X-Men by the Spider-Man villain Mysterio. Although most of the X-Men died in "Logan's" world too, they perished during one of Professor X's powerful psychic seizures at the X-Mansion in Westechester, New York. As the film shows, these psychic events paralyze everyone in the surrounding area, causing injury and death if left untreated.

In 2003's "X2: X-Men United," Brian Cox's William Stryker creates a twisted version of the mutant-detecting technology Cerebro to trick Professor X into killing every mutant on Earth. While his plan ultimately fails, it shows how Xavier's telepathic powers could be used to incapacitate and apparently kill mutants with a moment's notice. In "Logan," these seizures can only be stopped by injecting Professor X with a special serum. While it's not explicitly stated, this is likely the same temporary power-suppressing serum that Nicholas Hoult's Beast develops in "X-Men: First Class" and successfully uses in "X-Men: Days of Future Past."

5 POWER-ENHANCING DRUGS

Mutant growth hormone

Over the years, the X-Men have encountered more than their fair share of power-enhancing drugs. Whether they're called Mutant Growth Hormone, Kick, Rave, Zap, Banshee or Thunderbolt, these drugs all essentially work the same way. While there are differences in their various origins, they all temporarily enhance a mutant's powers, sometimes giving them increased strength and aggression, and can be fatal if used improperly or in high doses. In Marvel's Ultimate Universe, the power-boosting drug Banshee was derived from a sample of Wolverine's blood.

In the 2014 miniseries "Death of Wolverine," by Charles Soule and Steve McNiven, Wolverine uses the Regen Serum as a substitute for his absent healing factor. While Logan uses an unnamed serum for a similar purpose in "Logan," this formula was developed by Dr. Cornelius, the head of the Weapon X Program, in order to help his test subjects survive the adamantium-bonding process. In the comics, Logan uses this formula to accelerate his healing with no apparent side effects. In "Logan," the Regen Serum is combined with a power-booster to create a drug that can safely augment powers in small doses, but can burn out powers with overuse.

4 RICTOR

rictor x-force

Other than Laura, the most prominent member of the Transigen test subjects is Jason Genao's Rictor. As one of the corporation's oldest test subjects, Rictor serves as a de facto leader of the group and gives Wolverine the power-boosting serum. While Rictor has control over earth-shaking vibrations in comics, he appears to have powers derived from the earth-manipulating villain Avalanche in "Logan."

Since his debut in 1987's "X-Factor" #17, Rictor has had an extensive history bouncing around the X-Men's affiliate teams. Like his cinematic counterpart, the Marvel Universe's Rictor was originally rescued from a group of villains who wanted to use his powers for their own ends. After meeting the X-Men, Rictor was one of the young mutants who graduated from the New Mutants to X-Force. With both "The New Mutants" and "X-Force" set to be adapted into feature films, Rictor seems like a likely candidate to return in one or both of those movies, along with X-23.

3 ADAMANTIUM BULLET

Adamantium bullet

At one point in "Logan," Wolverine tells Laura that he carries around an adamantium bullet in case he needs to kill himself. Although Laura eventually gives this bullet a resting place inside X-24's adamantium skull, it wasn't the first time a Hugh Jackman character got shot in the head with that kind of bullet. In the controversial final moments of "X-Men Origins: Wolverine," Danny Huston's William Stryker shoots Logan with an adamantium bullet at point blank range, which causes Logan's famous memory loss.

Although that bullet was able to penetrate Logan's skull, his healing factor took care of the non-amnesia damage. With Wolverine's failing powers in "Logan," that same bullet would be fatal. Despite the cinematic importance of that type of bullet, he's been shot with adamantium bullets plenty of times within the Marvel Universe. Although these bullets have given Wolverine some catastrophic injuries, he's generally healed from them relatively quickly. There are even some characters, like the assassins White Ghost and Underworld, who specialize in using adamantium projectiles.

2 X-MEN CANON

x-men 2000

When the X-Men's cinematic timeline was reset in "X-Men: Days of Future Past," every other X-Men movie except the prequel "X-Men: First Class" was seemingly written out of continuity. Although "X-Men: Apocalypse," "Deadpool" and "Logan" take place in the revised timeline, the canonical status of the first few X-Men films wasn't clear. Thanks to some comments from Professor X and Wolverine in "Logan," it's been established that some version of the events from 2000's "X-Men" took place in a fairly recognizable manner.

Xavier states that he initially found Logan when he was cage-fighting, as he was in the beginning of "X-Men." They also reference an incident at the Statue of Liberty, where the finale of that film takes place. Wolverine also seems incensed at the mention of the word "Alkali," which suggests that he has at least some knowledge of the Weapon X Program's activities at Alkali Lake. He received this information in the closing moments of "X-Men" and it was a main setting in "X2: X-Men United." Despite this new information, some unexplained details, like Magneto and Mystique's roles in the Liberty Island incident, keep "X-Men" from being fully integrated back into the revised timeline.

1 THE DEATH OF WOLVERINE

Logan stands in crosshairs on the cover to Death of Wolverine

Although "Logan" was gently billed as a loose adaption of "Old Man Logan," the film takes a good deal of inspiration from the 2014 event "Death of Wolverine." In Charles Soule and Steve McNiven's miniseries, Wolverine's healing factor has been knocked out by an extra-dimensional super-virus. With a hefty bounty placed on his head, an increasingly frazzled Logan discovers that Dr. Abraham Cornelius is trying to replicate his adamantium-bonding procedure form the Weapon X Program. Wolverine finally dies, using the last of his Regen Serum to save Cornelius' test subjects.

In both "Logan" and "Death of Wolverine," Logan's failing healing factor plays a major role. While his actual death comes from a major injury in both stories, the side effects of his adamantium skeleton are slowly poisoning him in both. Logan also spends much of the film with a full beard wearing an increasingly bloodied and disheveled suit, a look that's taken almost verbatim from "Death of Wolverine" #2. While the specifics of his death are different in comics and film, he willingly sacrifices his life to save a young group of mutants in both, reminding audiences why he really is the best there is at what he does.

Stay tuned to CBR for all the latest developments in the X-Men Cinematic Universe! Let us know what your favorite "Logan" Easter Egg was in the comments below!