With roughly seven and a half seasons under its belt, Arrow just aired its 150th episode, "Emerald Archer." This massive achievement didn't go without celebration, of course. To mark the occasion, the team behind Arrow developed an episode in the style of a documentary, which centers on vigilantism in Star City.

Naturally, the anniversary episode brought with it a number of incredible references to Arrow’s past. This includes cameos from characters that have long been absent, and, obviously, a slew of Easter eggs. In the following list, said easter eggs, those both overt and subtle, will be recounted. Here are 10 easter eggs featured in Arrow’s 150th episode.

CHIMERA

chimera arrow episode 150 easter eggs

When its time to give the episode’s villain a codename, the best Curtis can think of is Chimera. Sure, the team could’ve used Cisco’s naming expertise. Chimera works, though. It’s a bizarre moniker for a bizarre character, who attacked his idols, people who saved him, just because he wanted their masks as souvenirs.

Thus explains the the genius of calling him Chimera. In the comics, numerous characters, aligned with the side of good and evil, have held the title. A Batman rogue from the 1980s went by Chimera. There’s a shape-shifting Aquaman villain named Chimera. King Chimera is a JSA member. And the list goes on.

KELSEY GRAMMER'S NARRATION

Kelsey Grammer in Boss

To most, Kelsey Grammer is better known as Dr. Frasier Crane from the television series Cheers and Frasier. Yet, the actor’s distinctive voice has landed him an incredible amount of voiceover work, some of which includes narration. Some Arrow fans may be surprised to learn that it was Grammer narrating the 150th episode’s documentary segments.

While his narration only occurs during the episode’s first act, Grammer’s involvement is still quite notable. It’s also a neat tease at the in-show documentary’s production value, which appears pretty high given that it opens with the Warner Bros. Pictures theme and logo, a first for Arrow.

ADAM HUNT'S BUILDING

Adam Hunt Arrow episode 150 easter eggs

While the search for Chimera persists, Curtis rushes into Star City’s police station to inform the gang that he has a lead on the villain’s whereabouts. Apparently, the location in question is at 101 Federal Street. According to Oliver, and a plaque that appears later in the episode, this address houses Adam Hunt’s old building.

As many may remember, Adam Hunt was the Hood’s first target during Arrow’s pilot. While Oliver didn’t take the corrupt businessman’s life, the Dark Archer brought about his end during Season 1’s midseason finale, “Year’s End.” Seeing Oliver return to Hunt’s building, unmasked yet just as committed to his mission is a treat.

CHIMERA'S REAL NAME

Kevin Smith Green Arrow

At the end of the episode, an SCPD officer reveals Chimera’s real name, Kevin Meltzer. This is in reference to two of Green Arrow’s comic book writers, filmmaker Kevin Smith and Brad Meltzer. In the early 2000s, Kevin Smith’s run on Green Arrow revived Oliver Queen, returning the character to his vigilante mantle.

It remains one of the character’s most acclaimed series. When Smith departed the series, famed novelist Brad Meltzer stepped in. As far as DC Comics are concerned, Meltzer is arguably best known for his work on the Identity Crisis limited series, which was originally published in Summer 2004.

RAGMAN

rory regan on arrow

Rory Regan debuts in Arrow Season 5 as one of Team Arrow’s new recruits. Yet, after using his suit to absorb a nuclear blast, Rory leaves the team halfway through the season. Apart from interview footage in episode 150, he hasn’t been seen since. Sadly, the footage lacks information as to Rory’s current status.

There’s hope that he is still alive and helping people, however. According to Diggle, no one’s been able to contact him following Chimera’s assault on Star City vigilantes. But, considering Chimera’s other victims weren’t fatally wounded, it stands to reason that Rory survived the attack as well.

HUNTRESS

Huntress aims her crossbow in Arrow

As one of the first characters to learn vigilantism under Oliver’s tutelage, it is only fair that Helena Bertinelli, aka Huntress, earned a nod in the show’s 150th episode. Unfortunately, the character does not actually appear in present-day. Regardless, her mask being on display alongside those of Chimera’s other victims means she’s still around in some respect.

What that may amount to remains to be seen, though. As Diggle explains it, he and Oliver were unable to get in touch with her. This particular revelation seems odd, as Helena should be in prison, where she’s meant to serve a lengthy sentence.

SIN'S REAL NAME

Sin in Arrow Season

Sin has been strangely absent from the Arrowverse since early in Arrow’s third run. She features briefly in the 150th episode, though, during an interview for the documentary. During her interview segment, a tag on the screen reveals the character’s full name, Cindy Simone. Sin’s last name serves as the Easter egg of note.

It seems a reference to Gail Simone, the writer responsible for the character from whom Sin is derived. In the comics, Sin is a young Asian girl that Black Canary meets, who’s training to succeed Lady Shiva. Obviously, the show has taken Sin’s character in a completely different direction.

BLACKSTAR'S REAL NAME IS MIA

Blackstar on Arrow

Blackstar is still new to the Arrowverse, thus far only appearing in the flash-forward segments of two episodes. In addition, information concerning her identity remains under wraps. However, it’s known that she participates in cage matches and seems adept with technology.

These hints, among others, lead many fans to believe that Blackstar is, in fact, the daughter of Felicity and Oliver. During episode 150, Mia is revealed as her first name, further adding fuel to the fire that she’s a Queen. A Mia Dearden appears in the comics as Green Arrow’s sidekick, Speedy; Arrow’s Thea, of course, is a version of this character.

CONNOR

legends of tomorrow connor

In the flash forward to year 2040, a character named Connor travels to the abandoned Arrowcave with Blackstar, aka Mia, who may be Oliver’s and Felicity’s daughter. Suffice it to say, Connor is likely Diggle’s son. During Legends of Tomorrow’s “Star City 2046” episode, Connor debuts as Diggle’s child, Connor Hawke.

Since that timeline was previously erased and takes place prior to “Flashpoint,” there’s no way this Connor is the same man. However, it seems a name change is still in order for John Jr. Or, perhaps, Lyla and Diggle will soon welcome a second child in the present-day timeline.

 WARNER BROS. PICTURES THEME

wb logo arrow episode 150 easter eggs

Following the standard DC logo mixed with Arrow-centric graphics in episode 150’s opening, another logo and theme sequence runs. This time, the sequence belongs to Warner Bros. Pictures. It is a clever touch, adding to the idea that a reporter in Star City has received funding to film a documentary about vigilantes, titled, “The Hood and the Rise of Vigilantes.”

If nothing else, the WB theme makes the production appear all the more realistic, while also signifying the documentary’s high quality. The brilliance with which such a framing device was developed and executed should serve as proof enough, though.