To most people, Mark Hamill is known for his iconic role as Luke Skywalker in the Star Wars series. Since 1977, Luke captured the imaginations of countless fans, who all got to watch his story progress from a young, impetuous farm boy, to an old and wise Jedi master. But, what many may not know is that Hamill had and continues to nurture a quite prolific voice acting career.

A few of his voice acting roles include Chucky in the most recent take on Child’s Play, Arnim Zola in the animated series Avengers: Assemble, and even returned to his old stomping grounds in Star Wars: The Clone Wars as Darth Bane, the only time the character has been seen outside of comics and novels. Surprisingly enough, his most iconic voice role is one that is the polar opposite of his most iconic live-action role, and one he didn’t even think he’d get at all.

Batman: The Animated Series started in 1992, and when the voice actors were being cast, Hamill decided to throw his hat into the ring for the role of Batman’s arch-nemesis, the Joker. “When I went in [for the Joker role], I thought, ‘You think they’re gonna hire Luke Skywalker to play the Joker? The fans will lose their minds!’ I was so sure that I couldn’t be cast,” Hamill said. He even said that he had no nervousness going in to audition because he knew he couldn’t get it, but he was shaken to his core when he actually was cast.

As ironic as it may be, it was the casting of Michael Keaton as Batman in 1989’s Batman film that helped him. He said, “there was this big outcry that Michael Keaton was gonna play Batman. ‘Oh, he’s Mr. Mom, he’s a comedy actor.’ I mean, they hadn’t even seen him [in the role] and they didn’t realize how great he would become. But, there was great controversy.”

Hamill went on to play the Joker in Batman: The Animated Series, which ran for 85 episodes and became so iconic in the role that he’s even played him in countless other media based around the caped crusader.