The Arrowverse has had a tumultuous run on the CW. The series of shows placing some of DC's finest comic book heroes front and center has been everything from stellar to confounding for the many narrative choices showrunners have made. While the popularity of Arrow, The Flash, Supergirl, Legends of Tomorrow, and Black Lightning has ebbed and flowed, one thing has remained consistent: DC Comics Easter eggs. The makers of these shows have flown their DC Comics fan flags being sure to inject the makings of a more grand universe than the focal points of the characters we're seeing on screen. So, what are some of the best Easter eggs within the Arrowverse?

RELATED: The 10 Most Powerful Weapons In The Arrowverse, Ranked

10 Harley Quinn

In the second season of the CW's flagship series Arrow, the princess to Gotham's clown prince of crime made a brief appearance. While fans didn't have an opportunity to really take a peek at Harley Quinn, we certainly heard her unmistakable voice. As John Diggle and Lyla Michaels were in the middle of a heated discussion outside several Argus cells, Harley could be heard offering her expertise as a trained therapist. What's even more fun about this cameo is that Tara Strong, the voice of Harley Quinn in many notable animated outings of the character, voiced the line in this scene as well.

9 Green Lantern

In the first season of The Flash, we were offered a brief tease of the existence of the Green Lantern Corps within the Arrowverse. Ferris Air was Hal Jordan's stomping grounds as a test pilot in DC Comics lore. While Coast City and Ferris Air had already been named dropped previously in the Arrowverse, something Barry said sealed the deal on Hal Jordan's existence. He stated that Ferris Air in Central City was shut down after a test pilot had gone missing. Of course, Hal Jordan left Earth for a time during his journey to becoming the Green Lantern.

RELATED: Arrowverse's The Monitor Talks Crisis on Infinite Earths & Beyond

Then, season four of Arrow further confirmed Hal Jordan's presence when a man quickly walked by the camera during a bar scene wearing a pilot jacket and the name "Jordan" emblazoned on it.

8 Solomon Grundy

The makings of the hulking zombie known as Solomon Grundy were seen during season 2 of Arrow. Cyrus Gold, who becomes Solomon Grundy in the comic book world, was seen as part of Sebastian Blood's army. Gold managed to survive an injection of Mirakuru serum when others did not. While this granted him superhuman abilities, he still could not withstand the might of the shows leading hero.

Cyrus Gold's life ended when Oliver caused a copious amount of chemicals to spill on top of the Mirakuru-infused villain subsequently killing him. Of course, we all know that Solomon Grundy is, in fact, dead and was reanimated as a zombie. Unfortunately, we never saw Cyrus Gold return. But that doesn't eliminate the possibility that he is wandering about somewhere in the Arrowverse.

7 A World Of Speedsters

In season 5 of The Flash, we learn that the Arrowverse world is practically filled with all the speedsters that DC Comics could possibly give us. By this point, we've already seen countless speedsters make a debut with the series. But in one particular episode that sees Barry Allen and his future daughter traveling back in time to obtain equipment needed to confront Cicada, Eobard Thawn name-checks a few characters from DC Comics lore when trying to guess who Nora West-Allen was.

RELATED: Arrowverse's Superman Crossover Is Brandon Routh's Shot At Vindication

Thawne mentioned Jesse Chambers, Libby Lawrence, and Danica Williams. Jessie Chambers has already appeared in the show as Jesse Quick. Libby Lawrence, also known as Liberty Belle, was the mother of Jessie Quick, and Danica Williams is the Flash during the futuristic timeline of Batman Beyond.

6 Wonder Woman

It's easy to see how the Arrowverse is much larger than the narrow view we see week to week. Clearly, other DC Comics heroes exist. Wonder Woman is certainly one of them. The Legends of Tomorrow ensured that we received a glimpse of Themyscria during their time traveling crusade. This is where the crew decided to send Helen of Troy to avoid returning her to her feudal world in Troy. The label on screen for the island was telling enough clearly indicating that the island is Themyscira, the island populated by women amazon warriors that is home to none other than Diana Prince.

5 Smallville

At the start of the Elseworlds crossover event, something magical happened for Superman fans far and wide. A familiar tune emanated from the TV speakers as the camera settled on Smallville Kent farm.

RELATED: Crisis on Infinite Earths: Black Lightning Will Appear in Arrowverse Event

That's right, Remy Zero's iconic song "Save Me" that played through the intro of the Smallville series for 10 seasons accompanied the shot as fans grabbed a glimpse of the Earth-38 version of Clark and Lois. Unfortunately, it wasn't Tom Welling and Erica Durance like we'd all expect after an intro like that!

4 Bane

The ferocious venom-infused killer Bane has yet to make a physical appearance in the Arrowverse. If and when he does show his face, it's likely not going to be Tom Hardy behind the mask. It's even more probable that Bane will not be the same live-action version we knew from Christopher Nolan's The Dark Knight Rises. Regardless, that didn't stop showrunners from precariously placing a model of the exact Bane mask that Tom Hardy wore within the second Elseworlds episode. During the Arkham riot, the mask can be spotted as Nora Fries (Mr. Freeze's wife) scans multiple shelves.

3 Bruce Wayne

Arrow kickstarted the shared DC universe as we know it on the CW. Throughout its run, the show has frequently borrowed heavily from Batman's world. This not only includes Oliver's brooding demeanor which is a tonal shift from the Emerald Archer's comic book origins, but it also encompasses villains and storylines from Batman's world. For quite some time there was always the question as to whether Bruce Wayne existed in the Arrowverse.

RELATED: Arrowverse's Monitor Originally Believed He Was Playing A Different DC Hero

The showrunners were rather coy when approached on the subject always stating that they wanted to steer clear of Batman with Ben Affleck portraying the character on the big screen. It wasn't until season six that Oliver namedropped Bruce Wayne when discussing the idea of doctored Green Arrow footage with a mob of reporters. As prominent a figure as Bruce Wayne is in DC's world, he is sure to be a celebrity well-known throughout the world.

2 Swamp Thing

When Cayden James waged his war on Star City, he brought a few more details of the known Arrowverse into the mix along with him. One detail, in particular, was quite exciting. James stole the material for his bombs from the Sunderland Corporation. For those who are unaware, the Sunderland Corporation was an enemy of Swamp Thing. Most prominently, they attempted to capture the enigmatic creature for their own devious designs. Swamp Thing received his own show on DC's streaming service, but could he possibly be part of the Arrowverse?

1 Batman v Superman: Dawn of Justice

Lex Luthor has famously championed the downfall of Superman throughout the Kryptonian's history. Many times in Batman v Superman: Dawn of Justice, Jesse Eisenberg's version of Lex Luthor challenged Superman's status as a perceived god among men. At one point, Superman's statue is defaced with "FALSE GOD" emblazoned across his chest in the form of graffiti. Supergirl honored that legacy when Jon Cryer's Lex Luthor was determined to show the world that Superman was a "false god." He further referenced a poignant moment from the Zack Snyder film when he stated that he wanted to see the hero "bleed." Fans may remember that Batman's now-famous line from that film was provocatively asking Superman if he bleeds.

NEXT: Arrowverse's Batwoman: 5 Theories Explaining Why Batman Is Missing (& 5 That Don’t Make Sense)

| Designed by Colorlib