Celebrating the birthday of original Harley Quinn voice actress Arleen Sorkin,Batman: The Animated Seriesco-star Mark Hamill spoke about how the character was created. In recent years, Harley has become one of DC’s most popular supervillains, appearing in a vast variety of comic books, video games, movies, and television shows. It all started with an appearance in the original animated series in 1992, with Quinn debuting as the Joker’s sidekick in the episode, “Joker’s Favor.”

Initially,Harley Quinnwas written into the episode as a nameless crook, just one of Joker’s many assistants that help him carry out his crimes. As Hamill reveals in a recent tweet, that all changed when Sorkin was tapped to voice the character, creating Harley’s distinct voice and personality.

“In the script she was just an unnamed Joker ‘hench-wench’ w/ no discernible personality,“Mark Hamillsays. “When Arleen began reading her lines in that unforgettable voice so poignant & full of heart I nearly fell off my chair! She brought SO much more than was on the page & a legend was born.”

DC fans know what happens next. Harley very quickly becomes a standout character onBatman: The Animated Series, permanently serving as a fixture in the DC universe. With Sorkin still voicing the role, Harley would go on to be further developed in other animated shows likeThe New Batman Adventures,Static Shock,Superman: The Animated Series, and the web seriesGotham Girls.

Arleen Sorkinalso reprised the role in manyBatmanvideo games, including the acclaimed hit titleBatman: Arkham Asylum. Soon after, Sorkin retired from voiceover work, but the popular character she helped to create would continue to appear in DC content. Veteran voiceover artist Tara Strong would take over the role in theArkham Asylumsequels, using that same distinct accent that Sorkin had made famous for Harley Quinn.

After she was played by Mia Sara in aBirds of Preytelevision series, Harley was also brought to the big screen when Margot Robbie played a live-action version of the Joker’s main squeeze in 2016’sSuicide Squad. A big hit with fans, Robbie reprised the role for this year’sBirds of Preyand will be back in the black and red once again next year when James’s Gunn’sThe Suicide Squadreboot is released. Robbie is also planning another Harley-led movie that would team her up with Poison Ivy and Catwoman, so we’ll probably be seeing a lot more of Robbie’s version of the character in the future.

On the small screen, the sassy supervillain has also found success with her ownHarley Quinnanimated series. Now voiced by Kaley Cuoco (The Big Bang Theory), Harley’s voice may sound a bit different, but her trademark personality and mannerisms are all still there. In the show, Harley is tasked with coming up with a new team of supervillains to lead, determined to prove her worth following a breakup with the Joker (Alan Tudyk). The first two seasons of the series are currently streaming onHBO Max, and a third season has also been ordered. This news comes to us fromMark Hamill on Twitter.