While Green Lantern has yet to properly emerge in the Arrowverse, The CW’s DC TV Universe has teased the Emerald Knights for over 5 years. The franchise has over the years introduced bigger elements of the DC Universe, going as far as having icons like Superman around on a regular basis. Even characters like Batman and Wonder Woman exist within the Arrowverse. But there are still major DC players that have yet to properly arrive on The CW, and one of them is Green Lantern. Given that Warner Bros. has had tight grips on certain IPs in order to reserve them for the big-screen, the infamous Corps hasn’t been able to join TV’s Justice League just yet. However, that hasn’t stopped the writers behind the various Arrowverse shows from dropping references.
Across Arrow, The Flash, Black Lightning, Legends of Tomorrow, Supergirl, and Batwoman, there have been multiple occasions for The CW to utilize the Green Lantern mythology. Though the name “Green Lantern” has never been uttered, that hasn’t prevented the creators to use various characters or even famous locations related to the Emerald Knight. The Easter eggs and teases certainly increased in the later seasons, particularly on Arrow. With the character of John Diggle sharing multiple similarities with John Stewart, one of the most famous Green Lanterns, he became the source of many of these connections.
Arrowverse creator Greg Berlanti is currently prepping a Green Lantern series for HBO Max, which was established to officially exist within the new Arrowverse Multiverse. Little is still known at this point what Berlanti will do with the show. While it remains to be seen if there will be crossovers thanks to the reveal in Crisis on Infinite Earths, a door has certainly been opened. While we wait to see if the HBO Max drama interacts with The CW's shows, here is every Green Lantern tease and Easter egg in the Arrowverse (so far)
Coast City
When it comes to locations in the Green Lantern lore, Coast City is a staple element, as it is the home of Hal Jordan himself. Throughout Arrow - but also in The Flash and other shows - Coast City has been referenced multiple times. One of the times that the location was actually visited was in the Arrow season 4 premiere, via flashbacks. During Oliver's fourth year in his origin story, the future vigilante is seen chasing criminals in Coast City. Aside from these name-drops and brief visits, Coast City is usually given an Easter egg in the form of billboards. Perhaps one of the other Arrowverse shows will eventually revisit Hal's hometown.
St. Walker's Hospital
Another location that the Arrowverse has used to tease the Green Lantern mythology is St. Walker's Hospital, a psychiatric institution that has appeared three times in Arrow. The hospital was where Brother Blood's mother Maya Resik was being treated after being framed for killing her husband. Sebastian was actually the one who killed his father, and he ended up murdering Maya after Laurel Lance had gotten answers about his past from her. The name of the hospital is a nod to Saint Walker, who is a member of the Blue Lantern Corps.
Ferris Air
A major character connected to Hal Jordan is Carol Ferris, his long-time love-interest who has also been an enemy to him as Star Sapphire. While Carol hasn't appeared in the Arrowverse, her company has been established and featured multiple times. Ferris Air appears frequently on Arrow, but has also been seen in The Flash. In DC Comics lore it began as Ferris Aircraft before Carol become the owner and later rebranded it as Ferris Air. If the writers are going by the comics, that would establish Carol as being very far into her career. Perhaps Carol will finally appear on-screen on any of the shows in future seasons now that Ferris Air has been used for over 8 years in the Arrowverse.
Demolition Team
While Arrow tended to be heavily grounded in reality, it ended up introducing one of Green Lantern's sillier foes back in season 4. In the episode "Code of Silence," the Demolition Team is introduced to the Arrowverse with Rosie, Hardhat, and Jackhammer working for Damien Darhk. Similarly to Arrow, the group didn't last very long in the comics. Being focused on destroying buildings, the Demolition Team was definitely not one of the more challenging forces that Team Arrow has gone up against. Interestingly enough, Daniel Cudmore, who played Jackhammer, later appeared in The Flash playing the DC villain Gridlock.
Goldface
One of the villains that The Flash and Green Lantern share in the comics is Goldface, who has had a few appearances on The CW drama within the last two seasons. Introduced in season 5, Goldface was established as a metahuman gangster with gold-based abilities whom Barry had to take on in the 13th episode "Goldfaced." However, Keith ended up returning in The Flash season 6 in the 11th episode "Love Is a Battlefield" where it was revealed that he and Amunet Black used to be a couple. Whether or not he has had any encounters with a Green Lantern in the Arrowverse has yet to be explored.
Obsidian
Legends of Tomorrow season 2 introduced the Arrowverse version of the Justice Society of America. While the iconic league of heroes was only around for a handful of episodes, a particular Green Lantern-related character was introduced: Todd Rice a.k.a. Obsidian, who is the son of the Golden Age Green Lantern, Alan Scott. While his family linage is never explored in-depth, it turns out that Alan was actually supposed to appear in Legends of Tomorrow season 2. Concept artist and costume designer Andy Poon revealed earlier this year that he had designed a suit for Alan for the second season. But a last-minute decision from DC caused them to scrap Alan and introduce Hourman instead.
Susan Williams
Arrow season 5 introduced a very surprising character from the Green Lantern mythology who actually is related to Hal in the comics. One of the new characters that recurred throughout the season was Susan Williams, a reporter for Channel 52 and a critic of Oliver Queen's mayoral run in Star City. Susan ended up getting romantically involved with Oliver throughout Arrow season 5. While she's a minor player in the comics, Susan is actually married to Hal's brother Jim, making her the Green Lantern's sister-in-law. While she hasn't shown up since that season, it wouldn't be surprising if perhaps Susan has met Jim off-screen and gotten involved with him.
Roy Stewart
Arrow season 7 came with a personal story for Diggle when his stepfather was introduced for an episode. Things got even more intriguing when the name of Ernie Hudson's character was revealed to be Roy Stewart - creating another Green Lantern connection. With fans having speculated that Diggle was a version of John Stewart, the 19th episode "Spartan" opened the door of that possibly now being the case. In the comics Roy is John Stewart's grandfather, whereas in Arrow he was Diggle's stepfather. The episode explores their complicated relationship and leads to them eventually making amends at the end.
Tattooed Man
Black Lightning recently became part of the Arrowverse through the events of Crisis on Infinite Earths. But prior to the crossover, the DC drama had actually introduced a familiar Green Lantern villain through the character of Latavius Johnson a.k.a. Lala, rather than any of the three people to have used the name in the comics. Lala, who initially started as a member of The 100 gang, was killed and revived by Tobias Whale during the first season. But when Tobias was bringing him back, a complicated side-effect came with his resurrection, as Lala is haunted by the people he has killed. They also become tattoos on his body, which leads to Tobias dubbing him Tattoo Man - a recurring antagonist in Freeland.
The Hal Jordan Cameo
Even though Hal Jordan has never appeared on-screen properly, the Arrow season 4 premiere actually gave viewers an almost-cameo of the Emerald Knight. The flashback sequences open up with a shot of a man wearing a flight pilot jacket with the name "Jordan" on it. Given that this was during Oliver's visit in Coast City, it's fair to say that this was, without doubt, the first glimpse of the Arrowverse's Hal.
Missing Test Pilot
While Hal's Arrow cameo was set in the past, The Flash season 1 managed to establish his current whereabouts. In episode 22 "Rogue Air", while aiding Barry Allen, Captain Cold commented on Ferris Air being shut down. As Barry confirmed Snart's theory, he also goes on to mention that it got shut down after one of their test pilots disappeared. Even though Hal is never mentioned by name, it's obvious that he's the test pilot who went missing, which explains why he hasn't been seen for years. His disappearance could very well be the beginning of his origin story to becoming a Green Lantern.
Earth-2 Hal Jordan
Earth-1 may not have shown Hal having any relationships with the heroes, but on Earth-2, it's a different story. In The Flash season 2, Barry visits Earth-2 for the first time in the episode "Welcome to Earth-2," where he discovers that his doppelganger has a very different life. When visiting the West-Allen resident, Barry sees a phone with several speed dial buttons listed with various names. While fellow Justice League members like Diana and Bruce are shown, Hal is also a friend of Iris and Barry in this universe. What their dynamic was like hasn't been revealed and probably never will be, since the original Earth-2 was destroyed.
Earth-90 John Diggle
The Elseworlds crossover became a huge moment for fans who have subscribed to the theory of Diggle becoming Green Lantern in the Arrowverse. When The Flash of Earth-90 finally manages to reach the heroes of Earth-1, he dropped a bomb on fans. When Earth-90 Barry sees Diggle amongst the heroes, he greets him and notices that he isn't sporting a ring, before realizing that things are different on this Earth. That was as far as Barry went with teasing what Earth-90's Diggle is all about. This became a major milestone for fans of Diggle as his future as a potential Emerald Knight now seemed a lot more possible.
John Diggle’s Alien Gift
Leading up to the Arrow series finale, David Ramsey promised that long-time fans would be rewarded when it came to Diggle's potential destiny as a Green Lantern. While a ring ever emerges on-screen, it was hinted at, to say the least. In Diggle's final scene in the show's last episode, a mysterious object crashes on Earth right where he is at. When investigating what had knocked him into his van, Diggle discovers a mysterious box which has a green glowing energy shining inside. Even though viewers never see what Diggle was looking at inside the box, it implied that he had been given a ring. In a post-mortem interview, Ramsey and executive producer Marc Guggenheim stated that only time will tell where Diggle goes from that moment.
HBO Max's Green Lantern
A big surprise to come out of the recent crossover was when Oliver Queen revealed the new Multiverse to the viewers. Rather than just restart the universe, the Spectre had actually managed to reboot the Multiverse, which came with a montage of the new Earths. One of them was Earth-12, which sees a person flying in space with green energy all around them before cutting to a shot of Oa with the Corps. Despite the footage being used from the 2011 film, this was to establish that Berlanti's HBO Max show is officially set within the Arrowverse Multiverse. With Sinestro and two yet-to-be-revealed human Lanterns being the primary focus of Green Lantern, perhaps a crossover between Earth-Prime and Earth-12 will happen down the line.
Earth-2’s Alan Scott
While Legends of Tomorrow got to feature his son, Alan Scott has been established to have existed on Stargirl. Post-Crisis on Infinite Earths, Stargirl was established to exist on a revived Earth-2 featuring the Justice Society of America. During the early episodes, the Golden Age Green Lantern was revealed to have supposedly died with several other JSA members during their war with the Injustice Society. Not much has so far been specified about this Earth's Emerald Knight other than that Courtney Whitmore ended up taking the Green Lantern when beginning to put together the generation of the JSA. Even though Alan may not be seen, it has been confirmed that there are plans for the lamp which might be happening in Stargirl season 2.
It's always possible that Alan's daughter Jade will be introduced as the one to take up the mantle as the new JSA's latest Green Lantern. Even if the other Arrowverse shows on Earth-Prime may not see the Emerald Knight for the time being, at least Stargirl will explore the iconic hero in one way or another. The CW will be bringing back the franchise in January 2021, including the debut of Superman & Lois. While the writers can continue to drop as many Easter eggs as they want, hopefully, 2021 will be the year when Green Lantern gets a proper Arrowverse treatment.