Warning: The following contains SPOILERS for Harley Quinn season 3.

Harley Quinn season 3 made its grand return to HBO Max last week, delighting fans once more with the official start of "Harlivy." Harley Quinn (voiced by The Flight Attendant's Kaley Cuoco) and Poison Ivy (voiced by Lake Bell, Bojack Horseman) are going on two weeks strong, curled up in the Fortress of Solitude when the series picks back up.

But, of course, things quickly become demonstrably less chill and the duo must return to Gotham and the cast of crazy characters that has made Harley Quinn such a hit with both DC fans and general audiences. Created by Justin Halpern and Patrick Schumacker, who are also executive producers of the very different but equally amazing Abbott ElementaryHarley Quinn also stars an incredible ensemble voice cast. And now in season 3, it boasts cameos as hilarious as Billy Bob Thornton as himself.

Related: Harley Quinn Season 3 Cast & Character Guide

While at San Diego Comic-Con, Screen Rant spoke to Halpern and Shumacker about their favorite supporting characters to write for in season 3, why Harley and Ivy won't break up, and how polarizing Harley Quinn's Big Bad may be this season. Watch the video above, and read the interview in full below.

Harley Quinn Season 3 Jor-El Harley and Ivy in Fortress of Solitude

Screen Rant: We're at Comic-Con with the minds behind Harley Quinn. Last time we saw you, no one had seen Harley Quinn yet. It's been three years. What is the new experience like?

Patrick Schumacker: When we premiered the show, we had been working on it since like 2017. Animation takes a bit, and we've been working in a vacuum, so nobody knew what to expect. We had feelings as fans of how people might react, but that was it. And butterflies when we premiered it in the Indigo ballroom, in front of [thousands] of people.

Justin Halpern: I almost s--t my pants.

And you're not someone who does often.

Justin Halpern: [Laughs] I am someone! Unlike Lex Luthor, I am someone who s--ts his pants.

Patrick Schumacker: But now we've had three years or so of knowledge of the show and world building and all of that, and people have opinions. So, we were jittery again last night, wondering what people are gonna think. ...And the response seemed great; it seemed like we picked right back up where we left off. And I think people are going to be pleased this season. I hope.

What I'm not pleased about is the wait, as it has been almost as long since season 2. But thankfully you have assuaged us with Harley and Ivy, whose ship has come to fruition. What can you tell us about them moving forward as a couple?

Justin Halpern: Rest assured, they will not break up. We're not going to break up the couple. But as any couple where one person is a psycho and the other one is Ivy, there's going to be turmoil. This season is thematically [about] when you've been in bad relationships, how do you act when you're in a good one? And what kind of bad habits do you take from those bad relationships that then go into a good one and cause trouble?

But I think we're gonna see them go and do a lots of fun, crazy s--t. This is our approach to Harley, right? There needs to be a real emotional throughline that you could put in a grounded, live-action sitcom or drama. And then on top of that, we build all the crazy s--t into the show.

In the interim, I read The Eat. Bang! Kill Tour, which I thought was great. Did you get to build on that in terms of the relationship issues for this season, or was that not something that you looked at as much?

Justin Halpern: Shout out to Tee Franklin!

Patrick Schumacker: It was an interesting thing, because the timing of it all didn't quite work out perfectly so that it was like this perfect bridge. It was just a function of the timeline with our production versus DC Publishing's production.

We do have a second anthology coming out that takes place within the world of the show, [The Real Sidekicks of New Gotham]. It's a lot of our show's writers writing stories for it, and Tee is writing all the bumper stories. The framework is Tawny, the local Gotham TV host, telling all these stories about the real sidekicks of Gotham. And so each story was written by one of our show's writers.

What is so great about Harley Quinn - aside from Harlivy, of course - is that each of the supporting cast members could lead their own show. They're all wild and crazy. Who are you having the most fun with in season 3?

Justin Halpern: There's a really stupid Bane runner for the entire season that is just as dumb as we could possibly make it. Because Bane is so funny to us the more pedantic he gets about things, the runner for the entire season is he gifted Iby and Kiteman a pasta maker for their wedding. The expensive one. They didn't get married, and he wants it back. Ivy is like, "F--k you, it's ours. That's so rude."

It's just him over the course of the season dealing with the ramifications of that. That one, for me, is fun.

Patrick Schumacker: A couple of ones for me. Frank the Plant plays a much larger role in this season. He is very integral to season three.

And then Nightwing is a new addition. And it's funny, that's one of the characters that I was really nervous about, because our interpretation of him for our show is much more of a brooding, emo sort of [riff] on the Titans series version of Dick Grayson. He's kind of antithetical to the Dick Grayson of the comics right now. I love Tom Taylor's run on the comics right now. I think it's fantastic, and I think a lot of people love that.

We were doing this concurrently, and I'm like, "God, are people gonna hate that we're showing brooding Dick Grayson?" But at the screening, people seemed to really dig the Bat family stuff. He's trying to find his place in the Bat family, returning from Bloodhaven, and now Batgirl is in the family. He doesn't know her at all. "Who is this charlatan in the Batcave?" And it's a girl, so we have some fun with that.

Harley Quinn 3x02 Nightwing harvey guillen

I love the dialogue between the different versions of the DC universe, like how we have Amanda Waller here as well. In your universe, did James Gunn direct The Suicide Squad?

Justin Halpern: That's a really good question, actually. I think we had conversations around this, but then it started breaking our brains. Did we ever decide on that?

Patrick Schumacker: No. We definitely discussed it, but I don't think we ever definitively said. That's one of the show running things that we've learned over the years: don't ever commit to anything if you don't have to, so that you know later if you decide that you want to make it canon that James Gunn directed The Suicide Squad in the Harley-verse. But I think in this world initially, he was the Marvel guy.

There's a scene in the premiere of season 3 where Clayface is auditioning for the Thomas Wayne biopic that James Gunn is directing. Clayface is struggling, and in a last-ditch effort to be cast somehow or impress James Gunn, he turns into a vibrating chair because he overhears James Gunn say that he has back problems. And then he's like, "Sit on me, please." James Gunn sits on him, and he's the most comfortable chair that he's ever sat in.

One of the lines that ended up on the cutting room floor was James Gunn saying, "Oh my god, it's like Thanos snapped and I can feel my anus again." And then Clayface is like, "Who Thanos?" And then we're out of the scene. We thought it kind of broke the world, so we didn't keep it in there. But the audio exists somewhere.

Justin Hapern: We were trying to be really careful in this story about Clayface and doing this Thomas Wayne biopic that it would actually exist in the world. Because at certain point we were pitching this idea of like, "What if they were making an actual movie about the Joker within the world, and Harley doesn't like who was cast as her?" But it became too meta, and we brought it back.

Patrick Schumacker: In this version, Billy Bob Thornton plays Thomas Wayne. And Billy Bob Thornton voices himself as Thomas Wayne.

You mentioned Batgirl earlier, and I love Briana Cuoco. What is the experience of having Briana and Kaley both? How different are they in life?

Patrick Schumacker: I think they're pretty similar; they hang out a lot. And the way we record the show, with the exception of the pilot, everybody's recorded individually. There's not a lot of times where we get to people in the booth.

But they're so alike in their cadence and in their speech, that I think it works out. Especially this season in the show, where we start to see Harley and Batgirl become closer and find that commonality. I think it really underscores that theme, and that idea with those two characters that they are kind of sisterly - because they literally are.

Justin Halpern: And Briana's really good about tweaking the performance, so it feels very Gen Z. Because that was our take on Batgirl; that she's this Gen Z superhero and not as world wise as Harley is. She has a little bit of a do-gooder, Amy Poehler from Parks and Rec kind of vibe. And Briana really nails that. She puts a spin on it, so you make sure it doesn't feel like, "This sounds so much like Kaylee," because they're so similar.

Out of the new elements in season 3, what is your favorite thing to be introducing to the audience?

Patrick Schumacker: The thing I'm really looking forward to is in the middle of the season, when we find out who our antagonist is for this season; who the Big Bad is. And I think it's going to surprise some people. I don't think it's been done before in the DC universe - in the entirety of the DC Universe. [Laughs] Maybe it'll be polarizing. I don't know. I think it's pretty fun and unexpected, and that's what I'm looking forward to.

Justin Halpern: What am I looking forward to the most? Finishing production! No, we're done. I think I'm looking forward to [the fact that] we had a chance to be a little bit more episodic this season. The whole season is serialized, but we allowed for a little more deviation from like this train that's moving forward. We do a couple episodes that are not in Gotham - one specifically that's not in Gotham, that I think is really fun.

It allowed us to like play with Nora Fries a little more, and I love Nora freeze. I think Rachel Dratch's performance of Nora Fries is so funny. [I love] whenever we get to play with a character who has never really had any center stage moments in the comics, or in any run - or has been like a character only exists insomuch as they serve another larger character, which is what Harley was at the start. We like taking those characters and then giving them their own center stage moment. We did that a bit with Nora in one of the episodes, and I'm really excited for people to see that one.

Harley Quinn Season 3 Synopsis

Harley Quinn and Poison Ivy shocked

The mayhem and madness continue in season three of this biting and uproarious adult animated comedy series. Wrapping up their “Eat. Bang! Kill. Tour,” Harley Quinn and Poison Ivy return to Gotham as the new power couple of DC villainy. Along with their ragtag crew – King Shark, Clayface, and Frank the Plant - "Harlivy" strives to become the best version of themselves while also working towards Ivy’s long desired plan of transforming Gotham into an Eden paradise.

Check out our other SDCC 2022 interviews with the casts of The SandmanDungeons & Dragons and Lord of the Rings: The Rings of Power as well.

Next: All 15 New DC Characters Harley Quinn Introduces In Season 3’s Premiere

New episodes of Harley Quinn season 3 drop Thursdays on HBO Max.