WARNING: This Post Contains Major Spoilers!
With Justice League, DC Films the tradition of the genre, offering fans not one, but two post-credits scenes. Like with most Marvel Studios movies, Justice League has both a mid-credits and post-credits scene - one that offers a look at what's to come in the DC Extended Universe, and another that is just a pure bit of fun for DC Comics fans.
Read below for an explanation of what goes down in the Justice League's post-credits scenes!
Mid-Credits Scene: World's Fastest
The Justice League mid-credits scene sees Henry Cavill's Superman and Ezra Miller's Flash meeting on a country road to settle a matter teased earlier, during their battle with Steppenwolf: Which hero is faster?
Batman and Flash trade some trash talk before Flash lights a small firecracker and toss it in the road; when it pops, both heroes set off running / flying toward the camera, in a spectacular slow-motion fashion.
The scene references the long history of competitive racing between The Flash and Superman, which stretches back as far as 1967, and has been a recurring event in DC Comics, ever since. As for who is ultimately the "World's Fastest?" Well, that's the part creators love to tease, often without resolving.
Post-Credits Scene: Injustice League Rising
The Justice League post-credits scene opens in what is presumably Arkham Asylum, as we see the prisoner cells being opened for a count. Lex Luthor's cell opens and the villain is show facing the wall, strapped into a straight jacket. When Lex refuses to respond to the guard's command to step forward, the guard goes in to force his compliance - only to turn the prisoner around and find out it's not Lex at all, just a grinning mad man acting as his decoy.
We then cut to the back of a head, as a mysterious helmeted figure throttles forward on a speed boat at dusk, helmet tassels flapping in the wind. The speed boat approaches a much larger yacht, and the figure helmeted figure steps off, revealing himself to be none other than Deathstroke The Terminator!
Deathstroke walks onto the back deck of the yacht where Lex Luthor sits waiting, with champagne and a flock of pretty models surrounding him. Lex is his usual chatterbox self, talking about how he's seen Superman's return, and how he and Batman have formed their own League. Deathstroke seems annoyed to be hearing old news, as he removes his helmet, revealing the face of actor Joe Manganiello. Lex assures Slade Wilson/Deathstroke that he's not wasting his time, because he likes living; the real question that Lex wants to impress upon the assassin is simple: isn't it time that the villains form a league of their own?
This is of course a setup for the Justice League's rivals, The Injustice League, which is a collection of the individual Justice League heroes' arch foes, like Lex Luthor, The Joker, Cheetah, Black Manta, Sinestro, Deathstroke, Reverse Flash, and many others. Now that the Justice League has found its place as a team of heroic worldly protectors, their dark mirror image is slowly taking shape in response.
Justice League is now in theaters; Aquaman arrives on December 21, 2018; Shazam on April 5, 2019; Wonder Woman 2 on November 1st, 2019; Cyborg on April 3, 2020; and Green Lantern Corps on July 24, 2020.