Kirk "Man-Bat" Langstrom is to Curt "The Lizard" Connors. Really, regardless of where each character ended up, the only difference between their origins is the specific ailment they were trying to cure and the specific animal they were working on.
This might just be DC returning the favor since in Shotaro Ishinomori's original manga, Kamen Rider was very much an Expy to Batman himself: a super-intelligent hero aided by his loyal butler who operated out of a high-tech laboratory beneath his family's mansion. However, most of these elements disappeared or were altered when the story was adapted for television.
Carmine Falcone from Batman: Year One is made into one of Vito Corleone from The Godfather and introduces Falcone's family, who was similar expies for the Corleone children: his daughter, Sofia Gigante, is a Gender Flipped Sonny, while his sons, Alberto and Sonny are respectively ones for Fredo and Michael.
Calendar Man is used in a similar way to Hannibal Lecter, especially with Batman and Gordon going to him for help on the Holiday murders in The Long Halloween as Clarice Starling did with Hannibal on the case Buffalo Bill case in The Silence of the Lambs.
For one in the same property, Julia Lopez is one for Batman: The Animated SeriesCanon Immigrant Renee Montoya, including being an honest cop Gordon trusts, though it's implied she'd have a higher rank as the story implied she'll replace O'Hara as chief.
Robin (1993): Tim Drake was initially written as one of Spider-Man(Peter Parker). It's no secret that Chuck Dixon based Tim Drake's adventures on the first 50 issues of The Amazing Spider-Man (1963). Fans used to compare him to the iconic Marvel superhero, calling him the Peter Parker of Gotham.
The Batman Who Laughs from the Dark Nights: Metal crossover is inspired both visually and in motif by Judge Death — a heinous monster who slaughters his entire universe simply because he can, and is inspired to bridge the gap to other worlds just to be able to do it all again.
The Kali Corporation from Batwoman (Rebirth) is one of SPECTRE (down to the similar meanings of their logos), with a dash of Cobra Unit thrown in as well.
In the Catwoman story "Selina's Big Score", Stark is a blatant Expy of Parker, Villain Protagonist of a series of crime novels by Richard Stark. He also looks like Lee Marvin, who played Parker (renamed Walker) in the film adaptation, Point Blank (1967), of the first novel. (Darwyn Cooke, who wrote and drew the story, later went on to officially adapt the Parker novels to the comic medium.)
Batman himself was one initially to The Shadow, right down to the very first Batman story in Detective Comics 27note "The Case of the Chemical Syndicate" being a Serial Numbers Filed Off remake of "Partners in Peril", a Shadow pulp novel. It should be little wonder that in the very first stories, Batman did not have his one rule, but did have a pair of .45 Colt automatics, both attributes of The Shadow. Later, when DC held the license for The Shadow comic books, due tribute was paid when Batman and The Shadow teamed up for an adventure, and Batman flat-out says that he was inspired by The Shadow.
Max Shreck, as a Corrupt Corporate Executive associated with electricity and bearing the name Max, he could be a very loose take on Maxie Zeus. His gothic attire is also similar to Kirk Langstrom a.k.a. Man-Bat. He could be considered the Gotham equivalent of Lex Luthor, being a crooked businessman who wants to control the city.
The Red Triangle Circus Gang appear to be base Of The Joker's carnival of freaks from The Killing Joke.
Presumably Fred Stickley is base on Daniel Mockridge, Nygma's former boss in Batman The Animated Series.
Dr. Burton is base on Jeremiah Arkham, the former head of the Asylum, from the comics.
Batman & Robin: Poison Ivy is a mixture of Catwoman's rebirth origin story from Returns and The Riddler's Mad Scientist origin story from Forever. Stated by Joel Schumacher that his original intent was to have Nicole Kidman portray Ivy in Batman Forever, hence why (aside from Elliot Goldenthal's recycled score) Ivy and Chase's Sexophone motifs are so similar.
In The Dark Knight, you have Officers Stephens and Ramirez, who are Expys for Harvey Bullock and Renee Montoya, with the exception being that Ramirez is actually a traitor. Stephens on the other hand is Bullock right down to the toothpick-chewing but his name was probably changed so the film wouldn't have two characters named Harvey. (It's rumored that Ramirez was supposed to be Montoya, but was changed to an original character because of the revelation that she was actually a crooked cop.)
Live-Action TV
In Gotham, Jerome Valenska and his identical twin brother Jeremiah are the Joker in all but name, to the point that the showrunners left it ambiguous on whether either twin becomes the Clown Prince of Crime, which the latter eventually fulfills the role in the finale.
Summer Gleeson is a stand-in for Vicki Vale, and even has her red hair and her career as a reporter.
Josiah Wormwood of "The Cape and Cowl Conspiracy" is essentially a prototype Riddler for the show—a deathtrap specialist who uses riddles in his crimes and has an obsession with knowing secrets and matching wits. A few episodes later, the legit Riddler made his debut.
A rather blatant one of Johnny Cochrane (the attorney who helped get O.J. Simpson acquitted of murder charges) shows up as one of the Joker's lawyers in "Joker's Millions" He turns up again in "Over the Edge".
While Calendar Girl has additional gimmicks, she is obviously a Gender Flip and stand-in for Calendar Man.
"Mean Seasons" also features the GWB network, which even has a WB-style water tower. Also, Donna Day, one of Calendar Girl's victims, is an Expy of fashion editor Carrie Donovan.
Grant Walker could be described as "Evil Walt Disney."
Batman: Mystery of the Batwoman does not use Kathy Kane, the original Batwoman from the comics, and instead introduces the idea of Batwoman being a Collective Identity used by three different Canon Foreigners. The closest analogue is Kathy Duquesne, who like Kane, ends up in a romantic relationship with Bruce Wayne.
While Ellen Yin is an Asian-AmericanEllen Yindel and Ethan Bennett is the show's first Clayface, they are are more or less counterparts of Renee Montoya and Crispus Allen. Which is a bit funny because Renee Montoya originated in B:TAS and became a Canon Immigrant. Yin also heavily resembles Elisa Maza as she wears the same outfit and Ethan Bennett is a stand-in Two-Face as before his transformation into Clayface, he had a long friendship with Bruce and called Batman "Bats," a la Harvey from The Long Halloween.
Chief Angel Rojas is basically Harvey Bullock with a higher rank, a Race Lift to Hispanic, and lacks Bullock's more redeeming qualities.
Beware the Batman was intended to use some of Batman's lesser known enemies in place of his regular Rogues Gallery. However, this means that some of those B and C-list villains have had their characters tweaked to fit into the roles of more well-known adversaries.
Anarky; a grinning, white-faced maniac obsessed with Chaos is The Joker. His bizzare philosophical speeches on the nature of Order Versus Chaos and love of explosions puts him closest to the Heath Ledger portrayal. Anarky is an especially egregious example, as in the comics he is a purposeful and intelligent teenage Anti-Villain and champion of the downtrodden who was designed as to subvert Anarchy Is Chaos and Bomb-Throwing Anarchists, whereas the cartoon version is a giggling lunatic who creates mayhem and destruction for his own amusement.
Magpie; a sultry, kleptomaniac leather-wearing female villain with an obsessive crush on Batman is Catwoman. Specifically, as a severely unbalanced schizophrenic, the Michelle Pfeiffer version.
Humpty Dumpty, who uses toys and puzzles is The Riddler. In one episode he even imprisons Batman and several others in a maze of rooms with each one containing a clue to a larger mystery.
Tobias Whale, a physically deformed crime lord with an animal name is a more serious Penguin.
Professor Pyg, as an ecoterrorist, could be considered a very loose Poison Ivy analogue.
