While it's undoubtedly showing its age at this point, 1989's Batman movie by Tim Burton remains one of the most popular and influential comic book movies of all time. It was the first superhero film to treat its hero seriously, with the dark edge the comics had, and was enormously successful for doing so.
Sadly Batman '89 only got one sequel, Batman Returns, despite a third movie and a Michelle Pfeiffer Catwoman spin-off being planned. With the news that DC is finally choosing to carry on the adventures of Michael Keaton's Batman in a comic series later this year, it's exciting to consider how many classic Batman characters may finally get to appear in this universe.
Selina Kyle/Catwoman
By far the most obvious and essential character who has to return in the Batman '89 comic series is Michelle Pfeiffer's Catwoman. She is the only villain to survive in either of the Burton movies, and the end of Batman Returns clearly teased her return, which never happened. With the deaths of Max Shreck and the Penguin, Catwoman is left with a blank slate by the end of Batman Returns, so it will interesting to see what sort of direction writer Sam Hamm could take Selina Kyle.
Harvey Dent/Two-Face
If fans talk about the plans for Tim Burton's Batman Continues, one of the biggest would've been the reappearance of Billy Dee Williams' Harvey Dent, who would finally make the transition into Two-Face. Williams was offered an appearance in Batman Returns but turned it down, and Batman Forever replaced him with Tommy Lee Jones. Now the only hint of Williams' Two-Face is his brief appearance in The LEGO Batman Movie. Hopefully, the comics will finally tell this villain's origin story.
Harley Quinn
It's easy to forget that the beloved Batman: The Animated Series is mostly inspired by the Burton movies, which is why Catwoman and Penguin look similar to their Returns counterparts and The Joker's real name is still Jack Napier.
Therefore, it would be great if the most popular character introduced in The Animated Series, Harley Quinn, made her transition back to the movie universe in Batman '89. Artist Joe Quinones already has designs for Harley in the comic, and it would be interesting to see her brought in after the Joker's death.
Dick Grayson/Robin
One of the most interesting facts about the Tim Burton Batman movies, considering they basically set the public viewpoint of Batman as a loner, is that they were both supposed to feature Dick Grayson's Robin. In fact, the plans were so far ahead that Marlon Wayans was actually cast as Dick Grayson, and he continues to get royalty checks despite not appearing in either movie. The new comic is the perfect time to finally bring Robin into the '89 universe, and judging by artist Joe Quinones' sketches for the series, that seems very likely.
Jonathan Crane/The Scarecrow
Out of all the rumors surrounding Tim Burton's third Batman movie, one of the most compelling was the idea of Brad Dourif playing Dr. Jonathan Crane a.k.a. The Scarecrow. There was ultimately no truth to this rumor, but it was an awesome bit of fan-casting nonetheless, and now it can be made a reality in the new comic series. Moreover, Scarecrow and his hallucinogenic fear gas would be a compelling fit for Batman '89, and it would be interesting to see how the movie's Batman handles such a villain.
Edward Nygma/The Riddler
The one thing that was always likely for Batman Continues was that the main villain would be The Riddler, just as what happened with Jim Carrey on Joel Schumacher's Batman Forever. Since his over-the-top appearance played by Frank Gorshin in the '60s TV show, Riddler has been one of Batman's most popular adversaries. As such, Edward Nygma is probably one of the most likely villains to turn up in the comics, and he may even be based on Robin Williams, since the planned Batman Continues script was written with Williams in mind for Nygma.
Victor Fries/Mr. Freeze
If there was one villain who truly wasn't done justice by the Joel Schumacher Batman sequels, it was Mr. Freeze. While Batman & Robin hinted at the tragedy of the character, it was lost with the ice puns, spiky freeze-ray tank, and Arnold Schwarzenegger's exaggerated performance. Tim Burton liked to emphasize the tragic nature of his movies' villains, so Victor Fries being immortal but dead to emotions, forever searching for a cure to his frozen wife's illness, is something that would work well in the Batman Burtonverse.
Barbara Gordon/Batgirl
Batman '89 artist Joe Quinones has already sketched many characters for the series, and one of the most intriguing is his design for Batgirl. It takes the aesthetic for Batman's costume and gives Batgirl a sort of poncho-cape hybrid.
Barbara can also be seen alongside Commissioner Gordon in the mock poster Quinones created, suggesting that if she's in the new comic, she's back to being Jim Gordon's daughter rather than Alfred Pennyworth's niece. Regardless, it would be fantastic to see Batgirl in the Burtonverse.
Chip Shreck
This seems unlikely as he's hardly the most popular character in Batman Returns, but out of all the surviving characters in the two movies, the only one who's neither a traditional comics hero nor villain is Chip Shreck, the adult son of Christopher Walken's Max. While Max met a shocking demise through the lips of Catwoman, Chip would've inherited everything his father built. Indeed, most of Max's motivation in Batman Returns was in making a legacy for his son, so presumably, Chip Shreck would even get the power-sucking power plant that Max attempted to kill Selina Kyle to protect. If Catwoman is also back, she might not be happy if Chip's plans are similar to his father's.
Jack Napier/The Joker
If there's one rule with The Joker, it's that he never stays dead. Jack Nicholson's Joker is one of the most iconic villains in a comic book movie ever, and while it doesn't seem too likely that he survived, the comics, videogames like Batman Arkham Knight, and shows like Batman Beyond usually all find a way to bring The Joker back even after his supposed death. At the very least, Joker could have left a contingency plan in case of his death, or even a Will, which might be a good way to include Harley Quinn if she's the one enacting Joker's last insane scheme. In either case, fans shouldn't expect Batman '89 to run without a single appearance of The Joker.