The Joker and Batman have always enjoyed a complicated relationship, and Gotham highlighted that by making each iconic figure responsible for the existence of the other. Throughout various interpretations of the Batman story, the Caped Crusader and Clown Prince of Crime are presented as fated adversaries, two polar opposites destined to do battle until the end of time. However, some adaptations take that concept even further and instead of simply making the Joker and Batman's sworn nemeses, both characters are shown to be psychologically dependent on each other.
This symbiotic relationship can be seen to varying extents in comic stories such as The Dark Knight Returns, The Killing Joke and Sign of the Joker, as well as the films of Tim Burton and Christopher Nolan. These stories prove that, despite being bitter enemies, Batman and Joker feed off each other in a way that any psychiatrist worth their salt would describe as unhealthy and, in some cases, they each become the very reason for the other man's alter-ego to exist.
As a multi-season TV series and prequel to Bruce Wayne's days as a vigilante, Gotham is perhaps better positioned than most to tackle this subject. Although never directly referred to as "The Joker" on screen, the role is ably taken by Cameron Monaghan as twin brothers Jerome and Jeremiah Valeska. After Jerome's death, Jeremiah is revealed as the show's "true" Joker and his scenes with David Mazouz's young Bruce Wayne depict the pair's strange dynamic in a typically unique way.
How Batman Created The Joker In Gotham
Joker's obsession with Bruce Wayne in Gotham can be traced back to the days of Jerome, where the budding psychopath targeted the city's most famous orphaned billionaire intending to make a statement killing alongside his new Maniax gang. From there, Bruce's fighting spirit and indomitable sense of justice sparked an interest within Jerome that, following his subsequent resurrection, developed into an obsession, with Jerome doggedly hunting Bruce just as The Joker does Batman.
After Jerome's (proper) death, Jeremiah doesn't exactly need much convincing to take up his brother's hobby and as an employee of Wayne Enterprises, the new Joker already has a ready-made connection to Bruce. Accordingly, the back-and-forth conflict between the two becomes even more intense, and culminates in a showdown at Ace Chemicals in Gotham season 5, where a scuffle against Bruce accidentally sends Jeremiah into a vat of chemicals that gives him Joker-like mottled white skin. As such, it could certainly be claimed that Bruce Wayne himself helps to create The Joker in Gotham.
Later, in Gotham's final episode, Jeremiah is revealed to have been faking a comatose state because he was waiting for Bruce Wayne to return to the city, a reveal clearly inspired by The Dark Knight Returns that demonstrates just how vital Bruce is to the villain. Gotham's Joker is so dependent on his mortal enemy that he has no interest in wreaking havoc unless Bruce is there to watch.
How Joker Created Batman In Gotham
Unfortunately for Bruce, he is just as culpable in terms of being dependent on his nemesis in Gotham. Every comic book fan (and probably every non-fan too) knows that Bruce Wayne fights crime because of his parents' murders. While this is still the case in Gotham, the prequel largely sees Bruce working alongside Jim Gordon and the GCPD instead of as a lone vigilante. Even into the latter stages of Gotham's final season, it's difficult to see why Bruce would ultimately choose to work outside of the law.
This point is resolved in the show's second-to-last episode, as Bruce explains to Selina Kyle that his public feud with Jeremiah almost caused the destruction of Gotham City; in his mind, battling villains in the open is no longer an option. This change in Batman's origin story is a subtle but seismic move on Gotham's part, as it implies that, were it not for Jeremiah, Bruce's urge for justice could've been sated by becoming a police advisor, or other such legitimate civil servant, rather than a costumed hero who bashes criminal skulls on a nightly basis.
Fittingly enough, when Bruce completes his Bat-transformation and returns to Gotham, his first case is to rescue Jim Gordon and his daughter from Jeremiah. Although the scene is brief, it's fascinating to see Jeremiah's interest piqued at the appearance of Batman - finally, he has discovered a new worthy plaything other than Bruce Wayne... or so he believes. The fact that Jeremiah switches from complete disinterest in anyone other than Bruce to sheer excitement over meeting the Batman, without realizing the two figures are one and the same, perfectly encapsulates how intertwined these two characters are in Gotham.
As mentioned previously, Gotham is far from the first live-action Batman tale to introduce these elements, but it did, arguably, do it best. Both The Dark Knight and Tim Burton's Batman, for instance, do excellent jobs of highlighting how The Joker is a product of Batman but neither is able to make the opposite true since both films feature a mature, ready-made Batman. While this is undoubtedly effective in its own way, it doesn't quite capture the two-way symbiosis developed over many years of Batman comics. With the benefits of a TV format and a youthful Bruce Wayne, this is perhaps one area where Gotham outdoes its big screen cousins.