Harley Quinn's journey to the big screen has been an unusual one. Unlike most comic book characters, she didn't originate on the printed page. Instead, she came first to animation in Batman: The Animated Series 25 years ago, at the hands of writer Paul Dini and producer/artist Bruce Timm. When they first designed the character of the Joker's girlfriend, they were surprised by who she really played off of well in the series; it turned out she didn't compliment the Joker nearly as much as she did the main character: Batman.

"As a combination of Bruce’s tremendous design and Arleen [Sorkin]’s great voice work, it became very easy for me to write the character [of Harley Quinn]. I knew how she’s look and I knew what she’d say," Dini told Comicbook.com at the world premiere of Suicide Squad. "She became a great counterpoint for Batman, a contrast in a scene where something grim would be happening, and she’d just make a joke; it would give the scene a completely different energy. I think if the audience is really invested in the action of what Batman is doing, and you have a character who can do compliment that as far as humor goes, it’s going to hit the same way with the audience."

Now, seeing that character he's written in animation, comics, and video games come to life has been "pretty unbelievable," the creator, who still works in all three of those mediums regularly said.

"It’s been a real whirlwind, but it’s been tons of fun. We were down in Times Square and saw the giant Harley billboards and everything. It’s weird to have your creation looking down at you like Godzilla."

Dini is thrilled with Margot Robbie's performance, even before he saw the whole movie, thanks to the copious TV spots and trailers that were released ahead of time.

“Every clip that I’ve seen of Margot as Harley, she seems to have nailed it perfectly. When she’s introducing herself to Katana, when she’s walking around with the bat behind her shoulders, she just seems to have really channeled the true spirit of the character," he said. "Seeing that come alive is just amazing for me. I saw the shot yesterday of her and Joker in the therapy session getting ready to kiss, and I was just like, ‘That’s it, that’s my girl.’”

As for the character's future, she's not going to fade away anytime soon. DC Comics has brand-new first issues of both Harley Quinn and Suicide Squad (featuring her) on the stands this week, Warner Bros. has teased a spin-off solo film for her starring Margot Robbie in the early stages, and both her co-creators will be working on her in animation in the next year. Timm is working on the recently announced Harley Quinn and Batman animated movie for next summer, while Dini will bring her back to her roots in a new animated series.

“I’ve done some new cartoons coming up with her in Justice League Action that’s coming up later this fall," Dini teased. "I had a lot of fun working with her again, sometimes as a solo, sometimes pairing her up with Poison Ivy. I finished the last of those three weeks ago, and that was a lot of fun. So Harley’s still out there, still in animation, and everyone has a lot of fun when we get our hands on her.”

You can see Margot Robbie as Harley Quinn in Suicide Squad, in theaters August 5, 2016.