The new take on the Joker in Batman: Caped Crusader, voiced by Matthew Needham, presents a stark departure from previous iterations. Set in a stylized, noir-infused 1940s Gotham, this version of the Clown Prince of Crime is somber, rarely laughs, and harbors a desire to eliminate the city's "vermin." This radical reinvention has led some viewers to speculate about the character's influences, with one prominent theory suggesting a connection to Nazism.

Needham, in an interview with IGN, directly addressed these fan theories. "I could categorically say that that's not the backstory that we came up with," he stated, firmly denying any direct link between his Joker and the Nazi party. The voice actor elaborated that while the producers, including Bruce Timm, James Tucker, and Geoffrey Thorne, desired a distinct portrayal, their instructions steered clear of such explicit political affiliations. "They wanted a very, very different take," Needham explained. "And as you can imagine, it's a strange experience being in the booth inhabiting the Joker. You can't help, or I couldn't help, but kind of slide into the Joker gear as it was. And you start to get a little bit maniacal. You start to get a little gleeful. And it's really their brilliant direction and their vision and their direction which pulled me back to fit the form that they wanted, which was this very cold, very calculating, soft-spoken version."

While the series intentionally keeps the Joker's origins mysterious, Needham developed a personal backstory to inform his performance. He noted a surprising alignment with co-producer Geoffrey Thorne's own interpretation, suggesting the script implicitly hints at a dark past. However, this personal narrative did not involve any connection to Nazism.

The character's motivations and his fascination with Batman were also discussed. Needham posits that the Joker sees himself as a singular, supreme being and is intrigued by Batman's existence. "I think the Joker just wants to meet him and to maybe help him uncover his untapped potential, let's say," he remarked. While the Joker may have existed in the world independently, Needham believes Batman's presence emboldens him and sparks his imagination.

The Season 2 finale features a climactic confrontation where Batman appears to use lethal force against the Joker. Needham found this moment, where the Joker laughs as he is impaled, to be a thematic victory for the character. "I think it is a victory in some way. I also think for the Joker it's really intriguing and really interesting that he's been foiled. And I think there's something in him that kind of like gets the joke. Do you know what I mean?"