The crossover event Elseworlds revealed that a surprising number of Batman characters exist in the Arrowverse. While previous episodes of Arrow, The Flash, and Supergirl have made off-hand references to The Dark Knight and had some of his enemies make an appearance, for the most part, the Arrowverse hasn't explored the world of Gotham City until now.

Elseworlds explained the reasons for this somewhat, with Oliver Queen believing - like most of the world, apparently - that Batman is an urban myth created by the Gotham City Police Department to scare criminals into behaving themselves. Barry Allen, by contrast, fully believed in Batman's existence. This all seemed rather ridiculous to Kara Zor-El, who knew for a fact that Batman is real on her home-world of Earth-38 and is somewhat friends with her cousin, Superman.

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

What follows is a quick rundown on every character from the Batman comics whose existence in the Arrowverse was confirmed during Elseworlds. While not every character appeared on camera, the reality of them being in the Arrowverse was established either by context clues in the background, name drops by other characters, or more than a few clever Easter eggs.

Vesper Fairchild

Batman Vesper Fairchild and Bruce Wayne On A Date

Upon first arriving in Gotham City, Oliver suggests looking up Vesper Fairchild - a radio personality who knows everyone in town worth knowing. Oliver reveals that he met her several years earlier and that they may have had a one-night stand together, but he couldn't be certain as that was during his drunken playboy days. (It was later confirmed that they had, after she hung up on him.) In the Batman comics, Vesper Fairchild was a radio talk show host, the self-dubbed "Siren Of The Night," who dated Bruce Wayne exclusively for a time until she was killed as part of a plot to frame him for her murder.

Batwoman/Kate Kane

Elseworlds Ruby Rose as Kate Kane Batwoman

Kate Kane is introduced to the Arrowverse heroes after she pays their bail when they are arrested shortly after arriving in Gotham. Revealed to be Bruce Wayne's cousin, who is in the midst of trying to renovate the former Wayne Enterprises building, she assists them only because she hopes it will get infamous vigilante Oliver Queen out of her city faster. She later orders them out of her city as Batwoman when their efforts to confront Dr. John Deegan start a full-scale riot at Arkham Asylum. Despite this, she does seem to built a rapport with Supergirl, who is the only person that realizes Kate Kane is Batwoman after she uses her X-Ray vision to peek through Batwoman's mask. It remains to be seen if The CW will move forward with a Batwoman TV show or not.

Batman/Bruce Wayne

Batman with Arrowverse Heroes in Background

The Arrowverse's "Elseworlds - Part 2" revealed that Bruce Wayne disappeared from Gotham City some three years earlier, shortly after the last reported sighting of Batman. Nobody thought much of this, however, as many people left Gotham City after the rumors of Batman's disappearance, as Gotham City somehow found a way to become even more crime-ridden and generally awful. While it is never outright said that Bruce Wayne and Batman are the same person, Kate Kane doesn't correct Supergirl when she tells her in private that she thinks her cousin would be proud of what she's doing after they stop a riot at Arkham Asylum.

Related: Everything We Know About Batman In The Arrowverse

Alfred Pennyworth

Alfred Pennyworth Batman comic

Bruce Wayne's butler and foster father, Alfred Pennyworth, doesn't make an appearance in Elseworlds. Indeed, there's no indication one way or the other that he's still in Gotham City or that he disappeared as mysteriously as Bruce Wayne. Still, his existence is acknowledged in a rather humorous way: After telling Barry, Kara, and Oliver that they can use the Wayne Enterprises building as a base of operations, Kate Kane informs them that the WiFi password for the building is "Alfred."

Oswald Cobblepot / The Penguin

Elseworlds The Cell Door Of The Penguin Oswald Cobblebot

As Oliver Queen and John Diggle go in search of Dr. John Deegan's office in Arkham Asylum, they wander down a hallway past several cell doors. The first door they encounter says the cell belongs to O. Cobblepot - a nod to Oswald Cobblepot, aka The Penguin. This is rather unusual, as The Penguin is not considered an insane criminal in the comics, having made his nest at Blackgate Penitentiary on those few occasions with Batman caught the foul fiend in the act.

Dr. Pamela Isley / Poison Ivy

Elseworlds The Cell Door of Dr. Pamela Isley Poison Ivy

The next cell down the hall from The Penguin belongs to P. Isley, which is clearly a reference to Dr. Pamela Isley aka Poison Ivy. If the name were not a dead giveaway, someone appears to have painted a red rose on Ivy's cell door. Perhaps the decoration was a gift from Harley Quinn the last time she was visiting Arkham?

Basil Karlov / Clayface

Elseworlds The Cell Door Of Clayface Basil Karlov

Room 303 has a rather dirty door and is labeled "Karlo, B." While not quite as famous as The Penguin or Poison Ivy, most DC Comics fans will recognize this as a reference to Basil Karlo aka Clayface. While the character's origins have changed dramatically over the years and there have been several villains to use the name, the current Clayface in the comics was an actor who had his body chemistry changed by a discontinued make-up called Re-Nu, thus transforming him into a shape-shifting mass of living clay.

Page 2 of 2: Riddler, Psycho-Pirate, Scarecrow, & More

Elseworlds The Cell Door Of The Riddler Edward Nigma

Edward Nigma / The Riddler

What's green and grey and covered with questions? Why, it's the next door down the hallway, leading to the cell of that King of Quizes and Master of Mindgames, Edward Nigma aka The Riddler. Unsurprisingly, the wall around Riddler's cell is decorated with green question mark graffiti and the riddle, "What is blue and grey and red all over?" (Best guess? It's either a dead Batman or The American Civil War.)

Roger Hayden/Psycho-Pirate

Elseworlds Roger Hayden Psycho-Pirate

As a riot breaks out after Dr. Deegan opens all the cell doors to cover his escape, one inmate gleefully declares that the inmates are running the asylum now, before donning a golden, featureless mask. This person is Roger Hayden, better known as the Psycho-Pirate, and his golden mask is an artifact called The Medusa Mask, which allows its wearer to alter the emotions of other people. While he's better known to DC Comics fans as one of the few people in the DC Universe to remember the multiverse as it was before Crisis on Infinite EarthsPsycho-Pirate was originally an enemy of the Justice Society of America on Earth-2, who operated out of Gotham and most frequently fought Batman and the Alan Scott Green Lantern.

Nora Fries

Elseworlds Nora Fries

As the Arrowverse's heroes are trying to stop the rioting at Arkham Asylum, Caitlin Snow (later turning into Killer Frost) discovered a frantic woman in a storage room, muttering about how her cryo-stasis unit was shut down along with the locks, and how she needs to be kept cold, while trying to crack open a tank of liquid nitrogen. Though not identified by name, this woman is meant to be Nora Fries - the wife of Dr. Victor Fries, who was cryogenically frozen in order to save her life while he worked on finding a cure for the disease that threatened her life. While the details of this disease are rarely discussed in the comics, it would seem that this version of Nora Fries suffers from some form of mental illness, if only to explain why she's being kept on ice in Arkham Asylum.

Bane

Elseworlds Nora Fries With Bane Mask

As Nora Fries is digging around the storage room, viewers briefly see a familiar looking mask on one of the shelves. Film fans will recognize this as the mask worn by Tom Hardy in The Dark Knight Rises when he played the villain Bane. Sadly, for those hoping this means that the Arrowverse is the same reality as Christopher Nolan's movies, the circumstances surrounding Bruce Wayne and Batman's disappearances were significantly different from one another - and everyone knew Batman existed in those films.

Dr. Victor Fries / Mr. Freeze

Elseworlds Nora Fries and Mr. Freeze's Freeze Ray

When Nora Fries' actions accidentally bring Killer Frost to the surface, she quickly moves to defend herself by assembling a familiar-looking gun that attaches to the can of liquid nitrogen she was trying to open earlier. Even before audiences see her using it to knockout Killer Frost with a blast of focused ice, it's clear from the label on the case - which reads, "Fries, V." - that this belongs to Nora's husband, Victor Fries, aka Mr. Freeze.

Dr. Jonathan Crane / The Scarecrow

Elseworlds Box of Fear Gas Belonging to Dr. Jonathan Crane The Scarecrow

When Green Arrow and The Flash come to Killer Frost's rescue, Oliver Queen throws a lightning bolt at Nora Fries that rebounds and breaks a box full of test tubes that are labeled as the property of "Crane, J." Soon Oliver and Barry find themselves in a cloud of fog and suddenly fighting one another's worst enemies - The Reverse Flash and Malcolm Merlyn (played by John Barrowman). Fans of the comics will recognize the box as belonging to Jonathan Crane, aka Scarecrow, and the test tubes as being full of his infamous Fear Gas, which causes people to hallucinate their worst fears coming to life.

Dr. John Deegan / Doctor Destiny

Elseworlds Dr. John Deegan Doctor Destiny

By the end of Elseworlds, Dr. John Deegan has been left a desiccated husk of the man he once was, and locked in a cell at Arkham Asylum. This gruesome fate, coupled with his utilization of an artifact called The Book of Destiny, seems to affirm his status as an adaption of the villain Doctor Destiny. The comic book version of Doctor Destiny, who was a scientist named Dr. John Dee, had the power to bring dreams to life and alter reality on a small scale. While Doctor Destiny was originally a Justice League villain, he became more famous for his association with Arkham Asylum, having been portrayed as an inmate there in two classic comics - Grant Morrison and Dave McKean's Arkham Asylum: A Serious House on Serious Earth and the first book of Neil Gaiman's Sandman, Preludes and Nocturnes.

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