With six TV shows now part of the Arrowverse, a web series, an animated web series, and comic tie-ins, plenty characters are sure to continue to be introduced. But some aren't as noticeable as others, and I bet I have at least one on here that you didn't know actually existed in the Arrowverse. So, without further ado, the 10 biggest characters you didn't know existed within the Arrowverse:
Okay, a bit of a cheat, but I thought I should include him. If you watch Arrow, then you have probably seen the Season 4 episode, 'Haunted.' In that episode, John Constantine appeared. He was a great character and so far, that has been my favorite episode of the whole series. If you haven't seen Constantine, I urge you to please go and watch it, it's amazing!
This one went by really quickly, as it was just a cameo. But in Arrow's second season episode titled 'Suicide Squad,' Harley Quinn was shown as a prisoner for A.R.G.U.S., as a reserve member of the Suicide Squad. She was portrayed perfectly, even if it was only for about 10 seconds. The producers of the show actually had plans for her in the future, but because Margot Robbie will be playing the character in this year's Suicide Squad, they weren't allowed to use her anymore. This really sucks, though, because she had the potential to go from a great Batman villain to a great Green Arrow villain, just like Deathstroke.
Like I said earlier, Constantine was amazing, and with that amazingness came Jim Corrigan, otherwise known as the Spectre. This character wasn't in much of the series, but when he was in it he was awesome! The character Zed Martin, from Constantine, could see the future, and she saw Corrigan's future. She saw him with several bullet wounds, and surrounded by a green mist, which is likely his body being taken over by the cosmic entity, the Spectre. Emmet J. Scanlan was great as the character and I really want more of him, which I wouldn't mind if he had in a spin-off or a role in Legends of Tomorrow.
This is the one I thought I could surprise you with — Black Adam! Yes, he actually is in the Arrowverse! In the Arrow: Season 2.5 comic, which is canon, Khem-Adam (K-A) appeared. K-A led the extremist sect, Onslaught. They kidnapped a group of schools girls and K-A recorded a public announcement about his plan to lead the people back to the way of the old Gods. He let a General pick a wife. The wife, whose name was Mesi Natifah, killed that General, and before K-A could record him killing all of the girls and putting it on TV, the Suicide Squad broke into the cave where they were being held. Bronze Tiger took on K-A, but was forced to stab himself in the gut, killing him (which is why we haven't seen him on Arrow again).
Ravan Nassar, another member of the Squad, then confronted K-A but before they could fight they were stopped by Nyssa al Ghul and the Canary (Sara Lance), who took K-A to Nanda Parbat. He was taken before Ra's al Ghul, who allowed Mesi Natifah to use his sword and take a swing at K-A (Mesi actually went on to appear in one Season 3 episode of Arrow, and two Season 4 episodes, where she always fought alongside Nyssa). I don't think Khem-Adam is actually dead, or if he is, he has somehow already come back, maybe reincarnated like Hawkman and Hawkgirl. I really, really want to see a live action appearance, and I think as a Legends of Tomorrow villain he would be perfect, or even on Arrow itself.
Because of Constantine, the Spectre exists in the Arrowverse, and so does Doctor Fate, for the same reason. In the pilot episode, Liv Aberdine picked up a relic of Doctor Fate's helmet. I'm really hoping that since the cast and characters of Legends of Tomorrow are supposed to shift, Doctor Fate can become a member. And I don't mind if it's Kent Nelson, Hector Hall, someone else, or even a new character.
In Season 4 of Arrow, when Oliver Queen was talking to Felicity Smoak about giving her a codename, he said he wanted to call her Oracle but "that was already taken." The most likely option, is that Barbara Gordon is Oracle, in Gotham City. This could also possibly confirm that the Joker exists in the Arrowverse as well, because he is the one who paralyzed Barbara Gordon. Also, the Joker is the one who led Harleen Quinzel to become Harley Quinn, so maybe the Joker is a part of the Arrowverse after all. But with Oracle an official part of the Arrowverse, she all but confirms my next addition...
Yes, Batman. He does exist in the Arrowverse, but he may not yet. There are a couple pieces of evidence that show that Batman will exist in a couple of years, but he likely is already a vigilante in Gotham City. The first piece of evidence is from the very first episode of The Flash. In the episode, when Harrison Wells (Eobard Thawne) is looking at a newspaper from 2024, at the bottom it says "Wayne Tech/Queen Inc. Merger Complete." So it's likely that in the future Oliver Queen and Bruce Wayne will be doing some business together, and they'll find out that they're both Green Arrow and Batman.
The other piece of evidence is from Legends of Tomorrow. When Rip Hunter is talking to the whole team, he says, "I've seen men of steel die and dark knights fall." This has to be a hint at Vandal Savage taking down Batman and Superman in his battle to conquer the world. So we know Batman will exist, even though the most likely option is that he already does. Another small piece of evidence, but we know that Oracle exists, and she's likely in Gotham, so she has to be working with someone, most likely Batman.
When Rip Hunter says, "I've seen men of steel die and dark knights fall," he also references Superman. Superman is also known as the Man of Steel, so he will exist in the future, but he probably already does. The other way he exists, though, is Supergirl. That show is part of the Arrowverse, and Superman has appeared, even if they haven't shown his face. I call Supergirl's world Earth-3, and because Earth-3 has Superman, Earth-1 must have a doppelgänger.
The Question (possibly)
This one isn't exactly official, but I still thought people would like to know that the Question might exist in the Arrowverse. When Roy Harper came back to Arrow this season, he said he's been operating in Hub City. Hub City is where the Question (Vic Sage) lived and operated. I like to think of it as this: when Roy Harper moved, he moved to Hub City, there he was forced back into crime fighting for some time and eventually started working with the Question. Now, that would be a good Arrow spin-off: Red Arrow and The Question.
In the current season of The Flash, when Jay Garrick is talking to Caitlyn Snow, they bring up Atlantis City. On Earth-1, it's how it is in the comics, an underwater city, but on Jay's world, Earth-2, it's above water, and according to Jay, "One of my best friends is from there," and of course, he has to be talking about Arthur Curry, better known as Aquaman. Also — and I never knew this before the day I wrote this article — in a deleted scene of the pilot episode for The Flash, Joe West tells Barry Allen he needs to stop looking at these urban legends about "a man who can talk to fish," and "a guy who can bend metal." He has to be talking about Aquaman, and possibly Superman (I'm not sure who else), and even though it's a deleted scene and isn't canon, I like to think he is.
There you have it, my top 10 characters you (probably) didn't know existed in the Arrowverse. There were others I could have included, but they are very small, like Ted Kord, who we know exists because of Robert Queen's mention of him, and the various Kord Industries references, and Martian Manhunter and Red Tornado from Supergirl. There just wasn't too much to say about these characters. The biggest one that I didn't include, though, is probably the Green Lantern. He might've had a small cameo early in Arrow's fourth season, and in The Flash Season 1, someone mentioned a "missing Ferris Air pilot," which, of course, has to be Hal Jordan.