As with any comic book adaptation, the latest Arrowverse crossover, Crisis On Earth-X, was packed with tonnes of references and little hints towards things that have happened on page. It's become somewhat of a tradition in both movies and television series to throw little nods to longtime readers and fans of source material as both a sign of respect to stories that are being adapted, and a little challenge for viewers to engage in. The CW is a network that currently boasts four superhero properties - which'll soon become five with Black Lightning - and they all exist within the same fictional universe (besides Supergirl, but that's a technicality), so you can expect plenty of comic book history to be planted in each episode.
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Bringing together heroes from Arrow, The Flash, Supergirl, and Legends of Tomorrow provides more of an opportunity than most on-screen adaptations, purely because of the rich history behind many of the characters included. Some Easter Eggs will have been easily spotted by most comic book readers, but specifically in this Arrowverse crossover, only eagle-eyed viewers will have picked up on the Easter Eggs we've decided to round up for you.
SPOILER WARNING: The following article contains spoilers for this year's Arrowverse crossover, Crisis On Earth-X
Did you know Lobo is likely to exist in The CW's Arrowverse? Neither did we until the we saw the Supergirl portion of the four-part event. Lobo's transition to the big screen has been a long and troubled one, though there seems to be a chance he'll pop up on the small screen first. Viewers are welcomed back to National City at the beginning of the episode with Kara partaking in a fight with an unidentified alien.
When details are brought up about who, or what, Kara is actually facing off against, Winn questions whether the alien is from "deep orbit", or more specifically, a Helgrammite - a shapeshifting alien Supergirl's come up against before. The Easter Egg comes after that, though. Alex worryingly suggests that the alien could well be Czarnian - in DC Comics, only one Czarnian is alive, and that's Lobo. Whether it's just a tease or an indication of things to come, it was definitely easy to miss.
4. Vanishing Point
Supergirl's life is threatened numerous times throughout Crisis On Earth-X, but when Eobard Thawne goes to literally extract her heart, she threatens to get Superman involved. This doesn't scare Thawne one little bit though, as he reveals that he's come up against her cousin in the future, and he defeated him.
It's natural to assume this points towards the crisis that's been teased since The Flash series began, but it could also be referencing Time Masters: Vanishing Point. This miniseries was published between 2010 and 2011, pitting some of the most iconic DC Comics characters in unusual situations - one of those being Superman fighting Thawne alongside Rip Hunter, Green Lantern, and Booster Gold.
This may just be followed up in a later season of The Flash or another annual crossover, but for now we'll have to wait and see.
3. Dayton Optical Systems
Perhaps the most obscure of the Easter Eggs in this article, the evil Nazis from an alternate universe broke into a lab. This doesn't sound special at all, until you spot the sign on the building which reads "Dayton Optical Systems", which points towards Doom Patrol character, Mento AKA Steve Dayton.
In DC Comics, Dayton is one of the richest men on the planet, so of course he's going to own a business (or two, or three, etc). Raiding Dayton Optical Systems, the villains are searching for an object known as the Prism. It just so turns out that this Prism is red, and Mento's wife in the comics - Elasti-Girl - is killed by Madame Rouge. It's subtle, but it's definitely a sly reference!
2. Barry and Iris' Daughter
Now this Easter Egg is not confirmed, but it's very possible. While Barry is waiting at the alter for Kara to start singing as a cue for Iris to walk down the aisle, he's approached by a rather awkward and familiar-looking waitress. She was somewhat awkward and bumbling just like Barry has known to be, and had a striking resemble to Iris. It's a tad deeper than that, though.
What the waitress says is perhaps a telltale sign: “I’m really excited to be here. I mean, at a wedding! Any wedding! It just so happens to be your wedding," she says. “You love weddings?” Barry asks in return, to which she replies, “I really do. Actually, I don’t know, I just feel like this is going to be one for the ages. I’m really happy I got to see it.”
Inquisitively, Barry asks “have we met?” Though she almost overly-denies it. “No! No, I’m a complete and total stranger. Good luck up there! Just remember to say, ‘I do.'” This scene went on way too long for it to be thrown away as a random exchange, especially in a busy crossover, so there has to be some significance to it. Perhaps time travel plays and a part and it's indeed Dawn Allen? We're likely to find out in a later episode of The Flash, if it's true.
1. All-Star Superman
The Easter Egg most viewers would have missed is a reference to a page in the All-Star Superman comic. The crossover basically revolves around the evil version of Supergirl, named Overgirl, and her impending death due to being overly exposed to solar radiation. The Nazi versions of our beloved heroes really invaded Earth-1 because they needed Supergirl's heart to save her.
This development happened to Superman in the modern classic, All-Star Superman. Lex Luthor sabotages a set of astronaut's mission to explore the sun, leading Superman to travel inside the sun to save them - thus overcharging his cells with solar radiation and dramatically limiting his lifespan. It's not said why Overgirl has been exposed to copious amounts of radiation, perhaps she's had a similar run-in with the Lex Luthor on Earth-X?
This year’s four-part crossover “Crisis on Earth-X” airred across two nights, beginning Monday, Nov. 27 with Supergirl and Arrow (on a special night for one week only) and concluding Tuesday, Nov. 28 with The Flash and Legends of Tomorrow.