Given that The Joker is Batman's greatest nemesis, it is a given that he has appeared in almost every incarnation of the character in non-comic media. There have been several adaptations of The Clown Prince of Crime on the big and small screen, with the character being played by quite a few different actors.

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Not all of them have been successful, but each has their own unique facets and quirks that make them stand out from the rest. With all that said, there are some rather bizarre facts about these actors which helped in making their different incarnations special.

Caesar Romero's Troublesome Mustache

Actor Caesar Romero and his version of The Joker.

Compared to the more bloodthirsty incarnations of The Joker, Caesar Romero's incarnation from Batman 1966 is more of a comical prankster, with the actor doing a pretty good job with what he was given. However, Romero drew the line when it came to shaving his iconic mustache for the role.

According to Batman actor, Adam West, Romero refused to shave the mustache that gave him a career, so the makeup department merely painted over it. Back in the day, it wasn't such a big deal, but in HD, it's unbelievably distracting.

Jack Nicholson Was Involved With The Makeup

Jack Nicholson in The Shining and Jack Nicholson in Batman.

While Jack Nicholson's performance as The Joker was a key part of the marketing for 1989's Batman, his performance is one of the more underrated ones. This is a shame, as the actor delivered a strong performance, with the character's makeup being especially impressive.

Being an A-lister, Nicholson was given a lot of control over his character, including having final say on The Joker's makeup. Jack Nicholson, director Tim Burton, and makeup designer Nick Dudman (who was actually handpicked by Nicholson) eventually settled on a look that masterfully blended Nicholson's distinct face with The Alabaster Jester's iconic design.

Tim Curry Almost Voiced Him

Tim Curry in Home Alone 2 and Batman fighting The Joker on a roller coaster.

Everyone knows who played The Joker in Batman: The Animated Series, but most don't know that another actor with an iconic voice almost nabbed the part. Before Mark Hamill became the voice everyone identifies with The Joker, Tim Curry signed on to play him.

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Unfortunately for the It star, it wasn't to be, as not only did Curry get bronchitis, making him unable to voice the character, but Kevin Conroy said that producers felt his take was too scary. Hamill was then brought in to do the voice and the rest is history.

Mark Hamill Had To Stand Up To Voice Him

Mark Hamill and The Joker with Charlie Collins.

Mark Hamill is pretty much everyone's favorite Joker and there's a lot that went into his legendary performance as the character. According to Hamill, Director Dan Riba and more, when the cast of Batman: The Animated Series was gathered together, they were all seated in the recording booth, but Hamill couldn't just sit to voice The Joker.

Unlike the other voice actors, Hamill felt that he had to stand up in order to truly play the character. No one can argue that it didn't work, as Hamill's performance defined who The Joker was for millions of fans.

The Joker Was In Birds Of Prey

Roger Stoneburner, Mark Hamill, and The Joker in Birds of Prey.

No, not the recent Birds of Prey, instead, The Clown Prince of Crime made an unusual cameo in the failed 2002 television show of the same name. In a flashback that recreates the horrific scene from The Killing Joke, The Joker shoots Dina Meyer's Barbara Gordon through the spine, setting up her role as Oracle in the show.

Played physically by actor Roger Stoneburner, the character's voice was provided by Mark Hamill once more. However, Birds of Prey, while it has its moments and is a fun concept for TV, isn't the greatest thing the Luke Skywalker actor has tied his name to.

Heath Ledger Stayed In Character Between Takes

Heath Ledger in Casanova and The Joker in The Dark Knight.

If Mark Hamill is the greatest animated Joker, Heath Ledger was the greatest live-action Joker. A talent taken from the world far too soon, Ledger's performance in The Dark Knight was so strong he won a posthumous Oscar for playing a far more realistic Alabaster Jester.

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According to Harvey Dent actor, Aaron Eckhart, while the crew was getting things ready for the scene between Joker and Two-Face in the hospital, Ledger was in character muttering to himself and hovering around the set. Eckhart states that without speaking a single word to each other, they choreographed the scene beautifully.

Cameron Monaghan Legally Couldn't Be The Joker

Cameron Monaghan in Shameless and The Not-Joker in Gotham.

According to star, Cameron Monaghan, Gotham was under a lot of pressure from Warner Bros to minimalize the ties between Jeremiah Valeska and The Joker. Though Jeremiah managed to get the bleached white skin, there were other elements of the character that had to be scaled down.

For example, not only could the character not have Joker's iconic green hair, but under no circumstances could Jeremiah be identified as The Joker. Even when the character fell into the bath of chemicals towards the end of the show, he still couldn't be The Joker.

Jared Leto Denies Sending Margot Robbie A Dead Rat

Jared Leto, Margot Robbie, Joker, and Harley Quinn.

Jared Leto is quite an odd bird, so when the rumors that he sent Harley Quinn actress Margot Robbie a dead rat while filming Suicide Squad began to circulate, everyone bought it. That said, Leto has some thoughts on the subject.

Leto himself denies the rumor, claiming that he instead sent Robbie cinnamon buns. The stories of the antics that Leto got up to whilst in character as The Joker are so believably ludicrous that if he actually sent someone a dead rat, it'd be fairly tame in comparison.

Anthony Ingruber Made Three Joker Performances His Own

Anthony Ingruber and Telltale's Joker.

Telltale's version of The Joker from Batman: A Telltale Series and The Enemy Within is a unique portrayal of the character, making him far more sympathetic than prior incarnations, complimented by Anthony Ingruber's amazing vocal performance.

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In an interview, Ingruber chimed in on what brought the character to life, stating that his Joker voice was inspired by Jack Nicholson, Heath Ledger, and Mark Hamill. All three actors are somewhat audible in the performance, but none overshadow the uniqueness of the portrayal and Ingruber manages to use those inspirations to make the character his own.

Joaquin Phoenix May Not Have Been The Joker At All

Joaquin Phoenix and Arthur Fleck pulling his cheeks into a grin while in his Joker makeup.

Joaquin Phoenix's portrayal of The Joker has proven popular, as well as somewhat controversial, with the actor winning an Oscar for his performance as Arthur Fleck. But is Arthur Fleck the real Joker? Well, Phoenix has his own opinion on that.

Phoenix believes that Arthur Fleck is genuinely the man who will one day become Batman's greatest foe, but he and director Todd Phillips chose to keep it ambiguous. This creates a great mystery around the character that keeps Phoenix's haunting performance in the minds of the viewer.

NEXT: Batman: 10 Bizarre Facts About Batman Actors