Here is every single cameo in the Black Lightning ceased existing on separate Earths in the Multiverse and ed The Flash, Arrow, and DC's Legends of Tomorrow on the same combined world, Earth Prime.
In addition, Crisis On Infinite Earths was the Arrowverse's celebration of the past DC Comics TV shows and movies that paved the way and the crossover's finale also set the stage for DC TV series to come. For Superman fans, Crisis was even more special for including three versions of the Man of Steel, including the Arrowverse's Superman (Tyler Hoechlin), Justice League's Flash (Ezra Miller) appeared in Crisis Part 4 and came face-to-face with the Arrowverse's Flash (Grant Gustin). Overall, Crisis was a loving ode to DC Comics across all media; the crossover's conclusion venerated Oliver Queen (Stephen Amell) as the Arrowverse's founding hero who then enabled the Rebirth of the Multiverse.
Crisis also featured appearances by most of the Arrowverse's cast of superheroes as well as some of its notable villains. In Crisis Part 4, the Paragons traveled through the Speed Force to key moments of Green Arrow's past, encountering Oliver Queen's memories of his enemies Malcolm Merlyn (John Barrowman), Damien Darhk (Neal McDonough), Prometheus (Josh Segarra), and Elseworlds' evil Black Suit Superman. But a lot of the pure fun of Crisis were the cameos from other DC properties and the pure ambition of the Arrowverse's producers paid off with several unforgettable appearances. Here's every cameo in Crisis On Infinite Earths.
Alexander Knox (Robert Wuhl) - Earth-89
Reporter Alexander Knox from Tim Burton's Batman 1989 watched the antimatter wave attack Gotham City in "Part 1" of Crisis. The headline of the Gotham Gazette he's holding also indicates that Jack Nicholson's Joker returned from the dead to tangle with Batman (Michael Keaton) again.
Hawk (Alan Ritchson) and Jason Todd (Curran Walters) - Earth-9
Representing DC Universe's Titans, Hawk and Robin (the Jason Todd version) were shown in San Francisco reacting to the antimatter wave coming to destroy Earth-9 during "Part 1".
The Ray (Russell Tovey) - Earth-X
One of the only superheroes on the Nazi-controlled Earth-X, which was introduced in 2017's Crisis On Earth-X crossover, The Ray was powerless against the antimatter wave ravaging the multiverse in "Part 1".
Dick Grayson (Burt Ward) - Earth-66
Dick Grayson, the former Robin the Boy Wonder from the original 1960s live action Batman TV series, was walking his dog when he saw the antimatter wave above Gotham City, which made him exclaim, "Holy crimson skies of death!"
Doomsayer Signholder (Wil Wheaton) - Earth-38
Wil Wheaton appeared in "Part 1" as a doomsayer holding a sign that nodded to a similar person in Superman II, who held an identical sign when General Zod (Terence Stamp), Ursa (Sarah Douglas), and Non (Jack O'Halloran) battled Superman (Christopher Reeve).
Leonard Snart's Voice (Wentworth Miller) - Earth-74
"Part 2" shows Earth-74, where Leonard Snart aka Captain Cold is the voice and artificial intelligence of the Waverider, which Harbinger (Audrey Anderson) commandeers along with the Mick Rory of Earth-74 (Dominic Purcell) to serve as the time ship of the Paragons.
Bruce Wayne (Kevin Conroy) - Earth-99
Earth-99's Bruce Wayne was believed to be the Paragon of Courage in "Part 2", but Batwoman (Ruby Rose) discovered this former Batman was a twisted, broken shell of himself. Wayne was aided by Earth-99's version of Luke Fox (Camrus Johnson) and he killed his world's Superman, although the injuries he sustained in the battle doomed him to wear an exoskeleton.
Clark Kent (Tom Welling) And Lois Lane (Erica Durance) - Earth-167
On Earth-167's Smallville, shown in "Part 2", Clark Kent gave up his powers and his role as Superman to raise a family with Lois Lane on the Kent Farm. Meanwhile, Lex Luthor (Michael Rosenbaum) is serving out his term as President of the United States.
Kingdom Come Superman (Brandon Routh) - Earth-96
Brandon Routh reprises his role as Superman in "Part 2" of Crisis. The Paragon of Truth, Kingdom Come Superman aka Clark Kent suffered a series of tragic losses, including the deaths of Lois Lane (Kate Bosworth) and Perry White (Frank Langella). He changed the yellow on his S crest to black to symbolize that even when things are darkest, hope shines through.
Jonah Hex (Johnathon Schaech) - Earth-16
The Jonah Hex of Earth-16 tried to stop Mia Smoak (Katherine McNamara), Sara Lance (Caity Lotz), and John Constantine (Matt Ryan) from accessing a Lazarus Pet in "Part 2". This Jonah never met the Legends and became an ally, unlike the Hex of Earth-1.
