Arrowverse crossover event Elseworlds was packed with Easter Eggs for fans of DC Comics, as well as a number of other clever pop culture references and tributes. This is par for the course for the shows making up the Arrowversewhich have gone beyond merely adapting classic comic book heroes and villains in creating a whole new world and are now bringing whole storylines from the comics to life.

Fittingly this tribute to the various alternate realities making up the DC Comics multiverse comes at a time when the individual Arrowverse shows seem to have been pushing beyond the boundaries of what comics readers expect of a superhero show. This fall has seen Arrow sending Oliver Queen to prison, The Flash introducing a villain called Cicada whose only connection to his comic-book counterpart is the use of a lightning-shaped dagger and Supergirl fighting an anti-alien immigration movement. With the announcement that the 2019 Arrowverse crossover event will be based on Crisis On Infinite Earths, it doesn't seem likely that this trend of pushing the envelope will stop anytime soon.

Related: Arrowverse Characters Already Dead When The Elseworlds Crossover Begins

What follows is a rundown of Easter Eggs and references hidden within the narrative of Elseworlds. This includes nods to the comics, other adaptations of the comics in popular culture and some of the references and tributes to other films and TV shows.

DC Comics Elseworlds Logo

This year's Arrowverse crossover event took its name from a special imprint of DC Comics. The Elseworlds label is applied to any story set in an alternate timeline or possible future. This includes such stories as The Dark Knight Returns and Batman: Red Rain, which is set in a reality where Bruce Wayne becomes a vampire. The logo for the event is identical to the Elseworlds logo used by DC Comics.

The Book Of Destiny

Destiny of The Endless

The book which Dr. John Deegan is given is later named as The Book of Destiny. In the DC Comics universe, Destiny is one of The Endless - seven god-like beings who exist as personifications of primal forces that humanity believes must have an intelligence behind them, like Death and Destruction. Destiny is the oldest of The Endless and has the duty of reading the book that details everything that has happened, is happening or will happen in the history of the universe. Though the book is usually chained to Destiny, it has been stolen in the past and used to rewrite reality, as in the 2007 Brave and the Bold series.

Red Skies In Morning, Heroes Take Warning

Elseworlds Red Skies and Lighning Storms

As the story shifts to Central City, we see the skies turning red and odd lighting strikes. This specific weather phenomenon has always been a sign of bad things happening to reality in the DC Comics Universe, with the first instance of this coming during Crisis on Infinite Earths. Similar weather was described in the future newspaper article detailing the disappearance of The Flash during a crisis of some kind in 2024.

Related: Every Easter Egg & DC Reference In The Flash Museum

Ivo Labs and Amazo

Elseworlds Amazo

First appearing in Brave and the Bold #30 in June 1960, Professor Anthony Ivo was a genius scientist obsessed with finding the secret of immortality. Professor Ivo also built Amazo - a robot capable of replicating the superpowers of any being it encountered. Shortly after waking up in Barry Allen's bed in "Elseworlds - Part One", Oliver Queen is sent to stop a robbery at Ivo Labs, where he accidentally activates the experimental Anti-Metahuman Adaptive Zootomic Organism that is later dubbed Amazo by Cisco. Amazo is revealed to have the ability to replicate superpowers thanks to a synthetic form of the miracle serum Mirakuru, which transformed Slade Wilson into Deathstroke.

Curiously, no mention is made of the Arrowverse version of Professor Ivo, who appeared in the flashback sequences of Arrow's second season. This version of Ivo piloted a ship called The Amazo around the waters of Lian Yu, searching for a sunken submarine containing samples of Mirakuru. Though he failed in his search and died, presumably Ivo left enough research behind for his company to create the synthetic form of Mirakuru that is said to empower Amazo.

Another Easter Egg comes later in the episode, when it is revealed that Ivo Labs is located on the corner of Waid and Augustyn, after the police are summoned to fight Amazo. This is a tribute to Mark Waid and Brian Augustyn - two former writers and editors on The Flash comic book. Augustyn is also notable as the writer of the first official Elseworlds story, Gotham By Gaslight.

Freaky Friday

Jamie Lee Curtis clutches her face as Lindsay Lohan looks on in Freaky Friday.

When Barry Allen and Oliver Queen discover that they have traded lives, Barry Allen compares the whole situation to Freaky Friday, one of the most famous films ever made involving body-swapping. Originally a 1972 children's book by Mary Rodgers, Freaky Friday has been adapted into four movies and a stage musical by The Walt Disney Company. Amusingly, though the movies saw a mother and a daughter trading minds, the original book only had the daughter experiencing her mother's life. The moral of the book - appreciate your parents - was also quite different from the movies' message of mutual respect and empathy.

Related: The Flash: 6 Biggest Questions After The First Elseworlds Episode

Quantum Leap

Quantum Leap Scott Bakula

One running gag in Elseworlds sees the geeks on Team Flash and Team Arrow debating if the body-swap is more like Freaky Friday or Quantum Leap. Airing for five seasons on NBC, Quantum Leap detailed the adventures of Dr. Sam Beckett - a scientist who traveled through time by trading minds with different people. Though the audience saw actor Scott Bakula dressed as the various people that Sam had taken over, almost everyone else saw the person Sam had possessed and Sam would see another person's face when he looked into a mirror. As Curtis Holt notes, the surest evidence they have that the body-swap occurred is the fact that "Oliver Queen" is educated enough in classic science-fiction to make the distinction between Freaky Friday and Quantum Leap and actually cares about the difference.

Smallville: The Series

Smallville Water Tower

As Barry and Oliver make their escape to Earth-38 in search of someone who will see them for who they really are, the audience is treated to a familiar sight and sound as we cut to the Kent farm."Save Me" by Remy Zero plays in the background, as we see the same aerial shot of a small rural town that appeared at the start of Smallville's opening credits. Sadly, there are no Tom Welling or Michael Rosenbaum cameos, but it's still a nice shout out to the long-running Superman series.

Strange Visitors

Adventures of Superman

As Clark is telling Kara about his and Lois taking a trip to Argo City so that he could finally learn something of his Kryptonian heritage directly, he describes himself and Lois as "strange visitors." This is a reference to the introduction of the very first Superman TV show, The Adventures of Superman, which described the Man of Steel as a "strange visitor from another world."

Superman: The Movie Reference

Superman flirting with Lois in Superman The Movie

After Cisco tracks Barry and Oliver to Earth-38 and informs them of the rampaging Amazo, Kara asks her cousin if he'd like to tag along and help. Cisco is agreeable but asks Clark, "Who are you?" Clark smiles and says "a friend," before opening his shirt to reveal his Superman costume. This whole exchange is a tribute to the moment in Superman: The Movie, where Lois Lane asks Superman who he is and he smiles and says, "A friend."

Related: Elseworlds Crossover Suggests Flash Is Faster Than Superman

The Day The Earth Stood Still

The Day The Earth Stood Still

After being defeated by Amazo, Ralph Dibny notes that the android "just Klaatu Barada Kickto’ed our asses." This is a nod to a famous line from the 1951 classic The Day The Earth Stood Still. It was here that the phrase "Kaatu Barada Nikto" was used to activate the robot, Gort.

It's Not Even Tuesday!

Elseworlds Harltey Sawyer as Ralph Dibny Elongated Man

As Cisco is inventorying all of the strange things that have happened - the red skies and lightning storms, Barry and Oliver trading lives, his sudden vision of The Monitor and the activation of Amazo - Ralph Dibny comments, "It's not even Tuesday!" This is a reference to the fact that The Flash, which normally airs on Tuesday nights, was airing at a special time on Sunday evening as part of Elseworlds. It's also a clever nod to the fact that, since many episodes of The Flash are specifically set on the same dates the episodes first air, most of the weirdness in Central City occurs on Tuesday nights.

A Familiar Style To Ollie's Speed Sketch

Elseworlds Jim Lee Sketch of The Monitor and John Deegan
A Jim Lee drawing of the Anti-Monitor and John Deegan used for the Arrowverse crossover.

The speed sketch that Oliver draws of John Deegan and The Monitor after Cisco shares his vibe-vision with Kara, Barry and Oliver may look familiar to DC Comics fans. This artwork was provided by Jim Lee - a legendary comic book artist, writer and editor who is currently employed as DC Comics' Chief Creative Officer. Lee is perhaps best known for his creation of the WildStorm universe and for being the visual architect of DC Comics' New 52 reboot.

Page 2 of 3: DC Easter Eggs In Elseworlds - Part 2

Elseworlds Grant Gustin is Oliver Queen Green Arrow

I Am Once More The Green Arrow

Typically Arrow opens up with a ponderous introduction, where Oliver Queen tells us his name, describes the current state of affairs in Star City and usually says he must become someone else or something else. "Elseworlds - Part 2" opened with an unusual variation reflecting the changed reality, where actor Grant Gustin was delivering the speech instead of Stephen Amell. The footage of this introduction matched the narration, with Gustin recreating various scenes from season 7 of Arrow, including being beaten up in prison and passionately kissing Felicity Smoak.

Related: Arrow: 5 Biggest Questions After The Second Elseworlds Episode

Green Arrow: The Original Vigilante

DC Comics Post-Crisis Timeline Cropped Green Arrow First Vigilante

Along with his belief that Batman is a myth, Oliver also insists that he is "the original vigilante." Technically, Oliver Queen would be right if the Arrowverse were wholly modeled on the timeline of Post-Zero Hour DC Comics. In this version of reality, which was the official canon from 1994 to 2005, Green Arrow was the first costumed vigilante to establish himself, just before the first public appearance of Superman ushered in a new Heroic Age. Oliver also anonymously financed the first incarnation of the Justice League, which was formed by The Flash, Green Lantern, Black Canary, Aquaman and Martian Manhunter after Green Arrow had started protecting Star City, according to JLA: Year One.

Christopher Nolan and Tim Burton Namedrop

Elseworlds Kara Danvers Barry Allen Oliver Queen Arrested in Gotham

When the Gotham City Police arrive as Kara, Barry and Oliver are being mugged, they are quick to call for back-up when they realize the notorious vigilante Oliver Queen is on the scene, even though he isn't resisting arrest. The officer on the scene tells dispatch that they are near the corner of Nolan and Burton. This is a nod to directors Christopher Nolan and Tim Burton - both of whom directed what are widely believed to be the best Batman movies of all time.

Batman 1966's Shakespeare Bust

Elseworlds William Shakespeare Bust

As Kara and Kate have a private talk in Kate's office, Kara notes that most corporate executives have "500 less tattoos" than Kate. Kate grins and flirtatiously replies that those are just the tattoos Kara can see. Embarrassed, Kara quickly changes the subject by admiring the bust of William Shakespeare, The Bard of Avon, that is lying in a nearby box. Fans of the 1966 Batman show will recognize this as the trigger which Adam West's Batman used to reveal the secret entrance to the Batcave in his study.

A Warning From The Flash

Elseworlds Batman V Superman The Flash Delivers A Warning

While Kara, Barry and Oliver are exploring Gotham City, the rest of Team Flash and Team Arrow are trying to solve the mystery of the weird weather. Noticing that the energy releases are similar to those of a dimensional breach, the technical geniuses try to build a quantum flux anchor to clarify the signal. For a few seconds, they are able to get a garbled message from the Flash of Earth-90, who tells them that they need to get the book from John Deegan to save their world. With its weird blue washed-out tint, bright lights and The Flash trying to deliver a message across space and time, the whole sequences is reminiscent of the future Flash trying to deliver a warning to Bruce Wayne in Batman v Superman.

Related: Arrowverse Superman's Black Suit Makes Up For Justice League's Biggest Omission

Arrow's Showrunner is in Arkham

Elseworlds The Cell Door of Marc Guggenheim

Just before they get to Dr. Deegan's office, Oliver and Digg see a cell belonging to M. Guggenheim. This is a nod to Marc Guggenheim - a producer and comic book author, who was the co-showrunner of Arrow for its first six seasons. He also, perhaps not coincidentally, wrote the teleplay for "Elseworlds - Part 2" and served as an executive consultant on Arrow season 7.

This isn't far from the only Batman references in Arkham: here's a list of every Batman character confirmed to be in the Arrowverse by Elseworlds.

Maybe Digg's Middle Name Is Stewart?

John Diggle Green Lantern Arrow

When the Barry Allen of Earth-90 finally does break-through to Earth-One, he recognizes John Diggle and asks why he isn't wearing his ring. This is a nod to a long-running fan theory that, eventually, Oliver Queen's best friend in the Arrowverse would become a Green Lantern, as a nod to the Green Lantern John Stewart and the classic Green Arrow/Green Lantern team-ups in the comics. Both Johns are career soldiers, though Diggle was in the Army and Stewart was a Marine.

Read More: Arrow: How Crisis On Infinite Earths Can Make John Diggle The Green Lantern

The Trigger Twins

Elseworlds Trigger Twins

When John Deegan uses the Book of Destiny for the second time, he transforms Oliver Queen and Barry Allen into a duo of powerless bank robbers known as The Trigger Twins. There are two groups of Trigger Twins in the DC Comics' history. One existed in the American Old West. The other was based in Gotham City in modern times. Both pairs were actual twin brothers.

Officers Merlyn, Wolfman and Diaz

Elseworlds Officers Merlyn Wolfman and Diaz

The second time he uses the Book of Destiny, John Deegan rewrites the lives of everyone on Earth One, making heroes into villains and vice versa. This new world is not unlike the twisted world of Earth-3 in the DC Comics multiverse. It's easy to miss in their brief time on screen, but the trio of Central City police officers who arrive to arrest the Trigger Twins near the end of "Elseworlds - Part 2" are all Green Arrow's enemies - Malcolm Merlyn, Kane Wolfman and Ricardo Diaz.

Related: Arrow: 5 Biggest Questions After The Second Elseworlds Episode

Page 3: DC Easter Eggs In Elseworlds - Part 3

Elseworlds John Diggle and Killer Frost

The Swapped Heroes & Villains Of Earth One

As The Trigger Twins go on the run in "Elseworlds - Part 3", we see how drastically the heroes of The Arrowverse have been changed. The Earth One version of Alex Danvers, Killer Frost and John Diggle are all members of a DEO-style peacekeeping force working with Superman out of what was STAR Labs. Cisco Ramon has become a crime boss and Jimmy "Superman's Worst Pal" Olsen is his head bodyguard. Even Gary Green from Legends of Tomorrow has had his destiny changed, now working as a bartender in Cisco Ramon's bar. He's still a colossal fanboy, though now the objects of his admiration are supervillains.

Scarface

Tony sitting at his desk in Scarface

Carlos Valdes' performance as the evil Cisco Ramon is particularly notable. Valdes seems to be paying tribute to Al Pacino's performance as gangster Tony Montana in Scarface. Apart from the first shot of "Mr. Ramon" sitting in his club counting his money resembling a similar scene from the movie, there is a certain swagger to Valdes' step throughout the episode that resembles Pacino's.

The Black Suit Superman

Elseworlds Tyler Hoechlin as Superman Black Suit

The black-suited Superman that John Deegan turns into seems to pay tribute to a few evil versions of Superman from the comics. A lot of his dialogue seems to have been inspired by Superman Prime - the sole survivor of a dead Earth who began destroying other worlds that didn't meet his high moral standards and may already have been referenced as having existed in the Arrowverse. The episode also seems to borrow a bit from the reality of Injustice: Gods Among Us, which saw the Batman of a universe where Superman became a fascist tyrant recruiting the Superman of another world to help him save his world. This is essentially what Barry and Oliver do when they escape to Earth-38 to get the real Superman's help against Deegan.

Deegan's actions as Superman also seem to be a stealth critique of Zack Snyder's vision of Superman in Man of Steel. Deegan's Superman hesitates when it comes to the choice between allowing The Trigger Twins to escape or saving a group of children from a falling crane, much like Snyder's Superman questioned the rightness of exposing his powers to save his classmates. Deegan's Superman is incredibly insecure, keeping a large support staff to build-up his ego, much as Snyder's Superman was unable to act until given a pep talk about how he had to be better than everyone else. And then there's the part where Deegan's Superman threatens to snap Barry Allen's neck...

Related: Justice League: Every Confirmed Change to Zack Snyder's Version

All The Various Superman Nods

Elseworlds Lois Lane Superman In Fortress Of Solitude

When we see Lois Lane on the Kent farm in "Elseworlds - Part 3", she is wearing a purple sweater. Lois Lane is frequently depicted in purple clothing in the comics, presumably so she'll stand out against the primary colors worn by Superman. The Lois Lane of Superman: The Animated Series was usually depicted in a purple blazer and white skirt for the same reason.

Lois and Clark tell Kara that they are pregnant and intend to stay in Argo City until their child is delivered. Lois specifically says this is because of the concerns over how hard a half-Kryptonian child could kick if they stay on Earth. While this line of thought was first introduced to the masses in Kevin Smith's Mallrats, it's actually a nod to a famous essay by respected science fiction writer Larry Niven, Man of Steel, Woman of Kleenex, regarding the problems Lois Lane would face in carrying Superman's baby.

Related: Elseworlds: 7 Unanswered Questions After This Year's Arrowverse Crossover

Later, when Lois and Clark are having dinner in the Fortress of Solitude, Lois is wearing a filmy blue dress. This resembles the dress worn by Margot Kidder in Superman: The Movie when Superman takes Lois Lane to fly around as part of an interview. The dinner itself is a tribute to a scene from Superman II. And while Superman turning coal into diamonds was a frequent stunt in the comics, he did it on-screen for the first time in Superman III.

More: When All Arrowverse Shows Return In 2019 (& What To Expect)