At the Annecy International Animation Film Festival, Collider's Steven Weintraub sat down with three of Prime Video's most visionary animation creators: Robert Kirkman (Invincible), Vivienne Medrano (Hazbin Hotel), and Sam Riegel (The Legend of Vox Machina). The trio discussed their hit shows, the freedom Prime Video gives them, and—most excitingly—what a mega crossover episode would look like.
While each series occupies a different corner of adult animation—superhero, musical fantasy, and D&D-inspired adventure—they share a commitment to pushing boundaries. All three have been renewed for multiple seasons, a rarity in today's streaming landscape. And they're all unapologetically original, even if Kirkman's Invincible adapts his own comics and Vox Machina springs from Critical Role's tabletop campaign.
The Ultimate Crossover: A Multiverse Musical
When asked to pitch a three-way crossover, the creators didn't hold back. Medrano suggested a multiverse approach to reconcile the shows' wildly different tones. Riegel joked, “Everybody loves multiverse shows.” Kirkman added a surprising condition: “That’s the only instance where I would allow an Invincible musical.”
Medrano loved the idea: “Oh, yes. That would be fun, actually.” Riegel imagined a show where his character sings, and at the end of every song, Invincible characters kill someone. “Somebody dies every time,” Medrano laughed. Kirkman concluded, “It writes itself.”
Which Characters Would Clash?
The group also debated which characters would become best friends—and which would try to murder each other. Medrano noted, “A lot of them would try to murder each other.” Kirkman was clear: “We’d have to leave the Viltrumites out. They’d just try to murder everybody.” Riegel then revealed a fun fact: J.K. Simmons (who voices Omni-Man) can sing. Medrano confirmed he's on the soundtrack for Guys and Dolls, and Kirkman added, “He’s the fucking yellow M&M.” Riegel, stunned, said, “We can make the show about the yellow M&M then.”
Creative Freedom and Full-Circle Moments
The conversation also touched on the creative freedom Prime Video offers. Medrano shared a raunchy tease for Helluva Boss Season 3, while Riegel reflected on the surreal experience of casting Andy Serkis. “I called up Andy Serkis’s agents and asked him to participate in my show,” he said. “My younger self would be astounded.”
Medrano recalled meeting her childhood hero, Invader Zim voice actor Richard Horvitz, who later became her voice director and close friend. “I've gotten drunk with him, gone to karaoke with him. It’s surreal.” Kirkman echoed the sentiment, naming Mark Hamill, Bruce Campbell, and Peter Cullen as legends he now works with. “I'm trying to cast Ed O'Neill in roles he's not right for because I want to work with him,” he joked.
These creators prove that adult animation is thriving, and Prime Video is giving them the room to take risks. For more on Prime Video's animation slate, check out our coverage of Why Prime Video's 'Being Human' Is the Supernatural Fantasy You Need to Binge and Ryan Gosling's 'Project Hail Mary' Becomes Prime Video's Biggest Sci-Fi Hit.
