As with every comic book movie that is part of a larger franchise, Justice League is bursting with Easter eggs and references. The Justice League Easter eggs found in the movie are some of the best the DCEU has yet offered. With so many legendary DC heroes on screen, there are tons of opportunities for references and nods to the source material. Zack Snyder didn't disappoint, setting fans to whooping and hollering at numerous points throughout the film.
While Justice League is receiving tepid reviews, comic book fans, and superhero fans in general, are apt to love it despite its flaws as a film. True DC fans, be sure to see the film before diving in - unless you don't mind spoilers and want to be able to keep an eye out. Heck, maybe even give Batman v Superman a re-watch. At any rate, be warned, there are Apokolips-tic spoilers ahead.
The Green Lantern Corps Make An Appearance
Justice League contains a flashback to an epic ancient battle between Steppenwolf and his cronies facing off against the allied forces of Atlanteans, Amazons, Men, the Old Gods (Greek Gods), and even a few Green Lanterns (the appearance of which will make the hardcore DC fans in theaters erupt.) Since this is indeed an ancient war, the identities of these particular Lanterns are unknown (though one look's like Salaak of Space Sector 1418), and one is even slain, after which we see his power ring take off in search of a new hero to take up the mantle.
The Green Lantern Corps will return to the big screen with their own movie in 2020, which will hopefully be enough time to heal the wounds inflicted by the Ryan Reynolds fiasco.
Aquaman's Hilarious Confession Is One Of Green Lantern's Comic Foibles
When the Justice League are on their way to thwart Steppenwolf, Aquaman has a seemingly out of character moment in which he starts baring his soul, talking about his fears of death and his hots for Wonder Woman. After a couple minutes of embarrassing secret spilling, he realizes he's sitting on Diana's Lasso of Truth, which compells him to open up. Hal Jordan the Green Lantern did this exact same thing in the comics.
The Flash And Superman Race To Prove Who's Fastest
The Flash and Superman have a long history of racing one another dating back to Superman (Vol. 1) #199 in 1967, and fans were treated to just that in Justice League. During the climactic battle, there's a moment where the two end up in somewhat of an organic race, which would have been enough, but then we were treated to a legitimate competition between the two in the mid-credits scene. Though, we don't actually get to see the conclusion of this scene.
The stakes laid down before Barry and Clark's race are as follows: If Superman wins, Barry has to take the team to brunch. Barry reluctantly agrees but says if he wins, "I get to tell them." Most likely meaning he gets to tell the other Justice Leaguers that he beat Superman.
Alfred Reminisces About The Penguin
Early in the movie, there's a scene between Bruce and Alfred in which the old butler laments this world full of new and cosmic terrors, saying something to the effect of, "One misses the days when one’s biggest concerns were exploding, wind-up penguins." This is an obvious nod to the infamous Batman villain, Penguin. It's a reminder that the DCEU's current Batman has been at this a long time and has faced villains even the most casual fans know.