The Dark Knight trilogy presents a gritty, realistic take on Batman, and a number of the Caped Crusader's villains not seen in the series could have been great antagonists for it. The Dark Knight trilogy first kicked off in 2005 with Batman Begins, showing Bruce Wayne (Christian Bale) in his origin story as Batman. Following the release of Batman Begins, The Dark Knight continued the story in 2008, with 2012's The Dark Knight Rises acting as the concluding chapter to the trilogy.
Christopher Nolan's grounded take on the Dark Knight was partially achieved by relying on Batman villains without powers or fantastical gimmicks like Ra's Al Ghul (Liam Neeson), the Joker (Heath Ledger), and Two-Face (Aaron Eckhart). With The Dark Knight trilogy having ended, this raises the interesting question of what other Batman villains would have fit within the tone of The Dark Knight trilogy had Nolan chosen to use them. When looking at Batman's vast rogues' gallery, there are five villains in particular who stand out as potential contenders to have been in The Dark Knight trilogy.
5 The Riddler
The Riddler had at one point been considered to be the villain of The Dark Knight Rises before Bane (Tom Hardy) became the movie's antagonist, which already shows how easily he could have been integrated into Nolan's films. One of Batman's scariest villains, the Riddler could have led Bale's Batman on in a cat-and-mouse game not unlike that of the Joker in The Dark Knight.
The Riddler is also malleable enough for a Nolan-style re-imaging to be easy to envision. Edward Nashton could have possibly been a past affiliate with the League of Assassins as a strategist or being a disaffected former political worker for Gotham's mayor. The Batman presented its own unique take on the Riddler, and it is not hard to see Christopher Nolan having a version that could have stood the test of time himself in The Dark Knight trilogy.
4 The Penguin
A major focus of The Dark Knight trilogy is the city being overrun by crime, along with Gotham City's elite thriving as the poorest among them suffer. Like Reeves's take on the Penguin, Nolan's version could have serviced both sides of The Dark Knight trilogy well, being shown as a formerly impoverished denizen of Gotham who clawed his way to the top of the city's underworld to become the Penguin.
As one of Batman's major villains, the Penguin's grounded, superpower-free nature would have positioned him well for Nolan's Batman films, while his famous trick umbrellas could have been easy to utilize as modified weaponry similar to Batman's own. Like the Riddler, the Penguin was later seen as a grounded villain in Matt Reeves's The Batman, played by Colin Farrell, and it is not hard to envision Nolan creating a similarly grounded yet totally distinct version of Oswald Cobblepott.
3 Hugo Strange
Outside of Batman Begins, Arkham Asylum was largely on the periphery of The Dark Knight trilogy, but it served its purpose while creating an environment where Professor Hugo Strange could have also been a villain in the series. Hugo Strange's association with Arkham in various Batman media would have enabled The Dark Knight trilogy to place a greater focus on the infamous asylum, while Hugo Strange himself could have been one of the darkest villains ever seen in Nolan's Batman films.
As a sadistic psychiatrist, Hugo Strange could also have pulled Bale's Batman into an Arkham-based conflict, either within the asylum itself or by unleashing its prisoners into Gotham City. Hugo Strange has also been seen in live-action thus far on the series Gotham, but he deserves more. As an institutional villain, he would have made sense alongside Jonathan Crane, aka Scarecrow.
2 Black Mask
Another of Gotham City's notorious crime bosses, DC's villain Black Mask made his big-screen debut in 2020's Birds of Prey, played by Ewan McGregor. He could also have been shown on the opposite end of the spectrum in The Dark Knight trilogy. The skull-like mask donned by Sionus is exactly the kind of symbol of terror that a villain of The Dark Knight trilogy would don to challenge Batman's heroism while concealing his own identity.
Furthermore, while Gotham's organized crime bosses were more of a backdrop element to The Dark Knight trilogy's main story, Black Mask could have been one to both emphasize that side of the Batman mythos along with bringing just the right amount of comic book flair to fit into the story. While Birds of Prey killed off Black Mask rather suddenly, Sionus could also have pushed the envelope of villainy in the way that Nolan consistently sought for the antagonists of his Batman movies to do.
1 The Ventriloquist
The Ventriloquist has never been adapted for a Batman movie, and he actually would have been more suited for The Dark Knight trilogy than he might appear to be at face value. The Arnold Wesker version of the Ventriloquist is one of the best known, having been featured on the acclaimed Batman: The Animated Series. The relationship of the timid, submissive Wesker perpetually bullied by his Al Capone-like doll made him stand out as a simultaneous villain and victim.
A version of Wesker in Nolan's Batman films could have undergone a re-imagining similar to that of Two-Face in The Dark Knight to emphasize the tragedy of his backstory, while the dark nature of Wesker's relationship with his doll could have been dialed up to 11 under Nolan's direction. While DC villains with metahuman or overly gimmicky leanings might have been a bridge too far for The Dark Knight trilogy, the Ventriloquist would fit well. He'd be both a physical and moral threat to the city, which works perfectly in The Dark Knight trilogy.
Batman's villains have a great deal of flexibility in how they can be portrayed on-screen, ranging from the camp of the Adam West '60s Batman series to the darker renditions of the Riddler and the Penguin seen in The Batman. Nolan's approach to The Dark Knight trilogy's arc, while a riveting story for the Caped Crusader, did also arguably make his take on Batman the version with the most tonal restrictions in place. Even still, for all the meticulous choices Nolan made with The Dark Knight trilogy, the unused Batman villains that could have thrived in the series are just as fascinating to ponder as those that did appear.
