Gotham is rife in Mythology Gags galore.
- In "Selina Kyle", Falcone mentions how a man about to die is honest, similar to The Joker's explanation for why he uses knives in The Dark Knight.
- In "Arkham", Fish Mooney has two people fight to the death for a job with her, much like Joker did. The Dollmaker is mentioned in the same episode.
- Also in "The Balloonman", the titular villain is introduced wearing a trench coat and a pig mask, referencing the somewhat obscure villain Professor Pyg. (Less obscure once the real Pyg shows up in Season 4.)
- Selina's nickname "Cat" obviously refers to her adult identity, but it also mirrors her earliest appearances in The Golden Age of Comic Books where she was called "The Cat" instead of "Catwoman".
- Going by the background of scenes set in her apartment, Barbara lives in a clock tower.
- Bruce listens to death metal in "Selina Kyle", like his LEGO counterpart.
- A shot of the Gotham skyline in "Selina Kyle" has a building with the Queen Consolidated logo, though this is not a sign of a crossover.
- It shows in "Arkham" they wish to make an "Arkham City".
- This is not the first time Nygma has worked for the GCPD.
- In "Viper", the first person to use the titular drug goes on an A God Am I spiel, causing someone to sarcastically call him "Zeus". This is a reference to Maxie Zeus, a lesser known member of Batman's Rogues Gallery who is defined by his delusion of being the Greek god of the same name.
- Also, the beginning of "Selina Kyle" has a sign for Trident Shipping, Maxie's company.
- Judging by the design of the (50s-vintage) license plates, Gotham City, despite shots of undisguised New York, is located in Connecticut, as it was in Young Justice (2010).
- As of "Harvey Dent", Selina Kyle is living at the Wayne Manor, just like she did in the comics on Earth-2 after she married Bruce Wayne.
- Alfred corrects Bullock who thought he was a valet.Alfred: I'm the butler.
- In "What the Little Bird Told Him", as Gordon's walking into the GCPD, Essen tells the gathered police that the commissioner is coming.
- From "Welcome Back, Jim Gordon" onward, Penguin owns a night club.
- In "Scarecrow", Jonathan Crane flees from his father and briefly stands in front of an actual scarecrow, referencing his eventual transformation into the eponymous supervillain.
- Falcone employs two of the future freaks and profits from that, just how in The Long Halloween he's the only member of the mob willing to work with the 'freaks' and profits from that.
- In "Red Hood", the Red Hood Gang's bank robberies and their habit of killing each other are reminiscent of the opening scene of The Dark Knight. Considering the comic-book connection between Red Hood and a certain Clown Prince of Crime, the parallel is very appropriate.
- This also isn't the first time Victor Zsasz worked as a hitman for Carmine Falcone.
- In "Rise of the Villains: Damned If You Do...", Cobblepot comments that having Selina around is "like having a cat around the house...but without all the dead mice."
- This is also not the first time Cobblepot and Selina work together.
- The fact that Oswald was manipulated by a corrupt mayor to succeed in his campaign rings a little bit familiar doesn't it?
- In "Knock Knock", Barbara's new hairstyle is similar to Selina's in Batman Returns.
- In the previously-mentioned episode, there are plenty of little nods to the Joker, most notably during the climax, where Jerome kills Sarah Essen (as the Joker did in the comics), and at the very end, he sends a chilling video message to the people of Gotham a la The Dark Knight (he also disguises himself as a cop, as he did in the film).
- In "The Last Laugh", Jerome shares a story about his miserable life with his abusive mother, another nod to The Dark Knight. He then mentions his dad asking him "Why are you crying?", which brings to mind the phrase "Why so serious?"
- When Jerome is killed in "The Last Laugh", he begins coughing blood, which drips over his mouth and gives him red lips. His face also goes deathly pale giving him white skin. He also dies grinning, as the Joker did in Batman (1989) and Batman: Arkham City. Much like other Joker incarnations, however, his death doesn't last.
- A big one for the Casting Gag of Michael Chiklis, who played an infamously corrupt cop on The Shield, in the even more corrupt city of Gotham — but as a by-the-book Da Chief.
- Paul Reubens was tapped to play Cobblepot's father, a nod to his already having done so in a memorable cameo in Batman Returns.
- Like Jean-Paul Valley in the comics, Theo Galavan is made into the Order of St. Dumas' holy warrior "Azrael", though the design of his outfit and sound of his voice resemble those of Phantasm.
- During Season 2, whenever Edward Nygma's dark side spoke, his voice would occasionally glitch out and distort (this prominently seen at the end of "Mommy's Little Monster"), similar to how the Riddler's voice would distort in the Batman: Arkham Series.
- In "Worse Than a Crime", Bruce tells Silver his favorite animal: owls. That won't last. note
- In "Mr. Freeze", the titular character delivers a threatening "I'll be back", which is hard not to see as a reference to another actor who's played the role.
- In "A Dead Man Feels No Cold", Victor's suit has a sort of retro-style, making it somewhat resemble the one he wore in his first appearance in the comics (when he was called Mr. Zero).
- Matches Malone, the man who killed Thomas and Martha Wayne. In the comics, Matches Malone is the name of a small-time crook whose identity Bruce Wayne assumes when he needs to go undercover in Gotham's underworld.
- In "Into the Woods", Bruce sews up a tear in Selina's jacket, leaving stitches reminiscent of Michelle Pfeiffer's outfit.
- In "The Gentle Art of Making Enemies", Jerome and Bruce face off in a house of mirrors, reminiscent of Batman: The Dark Knight Returns. Also similarly, Bruce uses his reflection(s) to trick Jerome into wasting his ammo.
- Another small nod to The Dark Knight Returns comes up just as Jerome is heading into the house of mirrors, namely that he calls Bruce "darling," like the previously-catatonic Joker did when he realized that Batman had come out of retirement.
- Jerome has his face cut off and worn by someone else. He then takes it back and staples it back on.
- The way Riddler is portrayed, particularly his mannerisms and even his voice, is like a toned-down version of Jim Carrey's Riddler in Batman Forever, with most of what's missing being Carrey's trademark zaniness.
- His giddy enthusiasm and frequent giggling seems to come straight from Frank Gorshin's version from the last live-action Batman show.
- Season 3 reveals a clone of Bruce Wayne, which may remind some folks of the Fully Absorbed Finale for Batman Beyond, where Amanda Waller planned to clone Bruce Wayne, leading to Terry McGinness.
- Season 3 has actor David Dastmalchian appear as one of Jerome's followers, Dwight Pollard. Dastmalchian also portrayed Thomas Schiff, one of the Joker's henchmen in The Dark Knight ten years earlier.
- In "The Primal Riddle" Selina is thrown out of a window and lands in an alley and she's swarmed by stray cats in a clear reference to Batman Returns.
- The ringtone of Nygma's cell phone is a sped-up electronic version of the scene-to-scene transition riff from the 1960s Batman.
- The Riddler making an illegal game show called "The Riddler Factory", just like in the same-titled comics one-shot
. - Upon reappearing in "Pax Penguina", Jonathan Crane is drawing his personal bogeyman on the floor of his cell at Arkham. The charcoal sketch looks exactly like how the Scarecrow appeared in Batman: The Animated Series.
- Even the "eye makeup under the Bat-cowl" controversy gets a nod! When Scarecrow removes his mask in "The Fear Reaper", Crane clearly does have dark brown makeup in a band across his eyes, which could be taken for a taunt at this minor inconsistency in several of the Batman movies.
- Professor Pyg's attack on the banquet in "Let Them Eat Pie" is likely intended as a twisted and violent parody of the scene in Batman: Year One where Batman crashes the banquet of Gotham City's corrupt elites.
- Might the unusual pronunciation of Martin's name ("Mar-teen") be a reference to David ("Dah-veed") Mazouz having heard his own name mispronounced a lot?
- Bruce's hallucination in "A Beautiful Darkness" includes a 1930s-style party at Wayne Manor that includes Gordon with a moustache and Cobblepot in a top hat.
- Gordon would later get a mustache properly in the series finale "The Beginning..." in order to make him look like his comic book counterpart, however he ends up shaving it off after only two minutes of screentime, as Gordon claimed it wasn't for him.
- In "That Old Corpse", the Mummer wears a Harley Quinn costume, but instead of white makeup has a porcelain face mask, similar to Alicia's in Batman (1989).
- In the same episode, after Jeremiah reveals that he succumbed to the Joker venom sent by Jerome after all, he wipes off makeup giving him a more natural appearance, revealing pale skin underneath. Jack Nicholson's Joker did the same thing, his skin being bleached after falling into the vat of chemicals and using makeup to appear more normal on a few occasions in the movie rather than the Joker's characteristic white skin being makeup like with some other versions.
- Jeremiah being an architect could be a reference to Batman: The Black Mirror, where Gordon referred to the Joker as "Gotham's darkest and most brilliant architect".
- Penguin repeatedly gets Mr. Penn's name wrong, calling him "Arnold" instead of Arthur. Arnold Wesker is the name of one of the incarnations of the Ventriloquists in the comics.
- One of the gangs◊ has a look that's clearly inspired by the Mutants from "The Dark Knight Returns."
- Bane's body language in the final episodes, particularly holding onto the front of his suit like suspenders, hearkens back to Tom Hardy's Bane from The Dark Knight Rises, and his voice even sounds a little like Hardy's version of the character. Also like in The Dark Knight Rises, this Bane is connected to the League of Shadows and his immediate superior is Ra's al-Ghul's daughter.
- In "The Beginning":
- Due to losing it in the last episode, Penguin gets an artificial right eye, like in the comics.
- At the start of the episode, Gordon has a mustache, like his comic counterpart, though he quickly shaves it.
- Penguin, Riddler, and Jeremiah all wear outfits that look almost exactly like their comic counterparts. Selina does also, though missing the comic suit's ears.
- Barbara's hair is now bright red like her daughter's in the comics. Interestingly, she closely resembles Dina Meyer, who played Barbara (Gordon) in Birds of Prey (2002).
- Jeremiah stops pretending to be braindead in reaction to Bruce returning to Gotham, just like how in The Dark Knight Returns the Joker emerges from actual catatonia in response to Batman returning to action.
- After killing Ecco, Jeremiah notes he can find someone else, in a clear reference to how she's a prototype for Harley Quinn.
- Penguin and the Riddler's first encounter with the Dark Knight involves him crashing down on the roof of Penguin's limo, just as he did on Falcone's limo his first night out as Batman in Batman Begins.
- When trying to figure out a new name, Jeremiah considers possibilities starting with "Jack". Jack Napier was one of the real names of the Joker on film and in the comics.
- For that matter, another he considers is John.
- Ecco disguises herself as an Arkham nurse when she assists Jeremiah, a reference to her counterpart's former job as an Arkham employee.
