Warning! This article contains spoilers for The Flash.The Flash's full list of cameos includes other DC characters with massive reveals in the film's final scenes.
Aside from the regular DC references and Easter eggs in The Flash, the film follows in the footsteps of previous multiverse-related superhero movies like Spider-Man: No Way Home and Doctor Strange in the Multiverse of Madness. While both films, like The Flash, slotted seamlessly into their franchise's story, the cameos and surprise inclusions offered plenty in the way of fan service. The same can be said for The Flash, with plenty of DC heroes from past eras appearing in the film's climax - and The Flash's post-credit scene, possibly hinting at the first confirmed superhero of James Gunn’s DCU.
Christopher Reeve As Superman
One of the first major appearances from another DC universe in The Flash movie's ending was Christopher Reeve as Superman. As the spherical multiverse became clear through the Speed Force, the film transported the audience to each one, allowing Reeve's Superman to appear as the protector of his universe. Viewing the cataclysmic event from the version of Metropolis seen in 1978's Superman and its various sequels, Reeve's Cal-El - albeit a complete CGI creation due to Reeve's ing in 2004 - was honored as one of the first cinematic variations of the Man of Steel.
Helen Slater As Supergirl
Alongside Reeve's Superman was another familiar face from that franchise, Helen Slater as Supergirl. Supergirl was released in 1984 as a spin-off of Reeve's Superman films, set in the same universe as Superman, Superman II, and Superman III before Superman IV: The Quest for Peace rounded off the five-film series in 1987. In The Flash, Reeve's Superman is seen first viewing the crack in the multiverse before Slater flies to his side as Kara Zor-El. Accompanying both characters is John Williams' iconic Superman theme, paying homage to one of the first genuinely successful DC franchises on film.
While Supergirl was a Superman spin-off, Reeve never appeared in the film. Initially, a cameo from the actor was planned before Reeve pulled out. Supergirl instead features Reeve’s likeness in a photograph as part of the film. As a result, The Flash pairing the two together - despite the ittedly shoddy CGI on display - is an extremely satisfying moment for fans of one of the first iterations of the Kryptonians on film.
Nicolas Cage As Superman
Perhaps simultaneously the most and least surprising cameo in The Flash is Nicolas Cage as Superman. The lack of surprise comes from director Andy Muschietti itting to Cage's cameo in a spoiler-filled reveal of The Flash over a month before it was released in theaters. However, anyone who managed to avoid Muschietti's interview will have been blown away to see Nicolas Cage as a multiversal Superman, given the film in which his character was originally supposed to appear never being released.
Cage was signed on to star in a film named Superman Lives, directed by Tim Burton after the success of the filmmaker's Batman films. That being said, the film underwent a long period of development hell, eventually being scrapped by Warner Bros. after the studio spent $30 million on the production. Regardless of what happened with Tim Burton's canceled Superman Lives, Cage got his chance to appear as Superman in The Flash, fighting off a giant spider before witnessing the crack in the multiverse caused by Barry.
Adam West As Batman
While The Flash's finale featured many references to the Kryptonian heroes of the DC Universe, the film also provided fans of Gotham's Dark Knight with much to cheer about. Though the references to DC's prior Batman franchises are much less clear than the various Superman references, Adam West's Batman can be seen in one of the multiversal spheres in The Flash. West is known as one of the first major live-action Batman actors, playing the character in the 1960s film and TV series Batman. Just as Keaton's Batman honors Burton's franchise, West's appearance does the same for a similarly iconic iteration of The Dark Knight.
George Reeves As Superman
As the multiversal section of The Flash is playing out, a black-and-white character can be seen in one of the spheres. This character is none other than Superman played by George Reeves. Reeves played the character in the 1950s TV series Adventures of Superman. While many though the scene in The Flash referenced Lewis Wilson as Batman, eagle-eyed viewers realized the scene was referencing Reeves' tenure as the Man of Steel.
A Golden Age Version Of The Flash
With the constant Superman and Batman references in The Flash's third act, one could be forgiven for forgetting that it is a Flash-centric movie. While the lack of other Flash actors of the past - such as Grant Gustin from the CW show The Flash for example - is disappointing, one cameo centered on the Scarlet Speedster is present in The Flash movie's finale. The cameo comes from a generic CGI creation of the Golden Age of the Flash from DC Comics.
At first, viewers thought The Flash paid homage to Teddy Sears. In The Flash on the CW show, Sears played the character of Hunter Zolomon. In the show, Zolomon eventually donned the name of Jay Garrick/The Flash, with many assuming it was Sears who had a cameo in The Flash film. However, the version of the Flash seen in the Speed Force was simply a CGI creation of the superhero, emulating the Golden Age of DC Comics.
Rather than be any specific iteration of the hero, The Flash's filmmakers instead opted to create the most iconic version of the superhero from the comics. Donning the iconic winged helmet, the CGI creation of the Flash in the movie evokes the classic appearance of the character at his peak in DC Comics. While actors like Sears and John Wesley Shipp have donned this costume in CW's The Flash, The Flash movie instead chose to recreate the iconic version of the titular hero many know from his many comic book runs rather than any specific iteration of DC's fastest man.
