You probably recognize that raspy, phlegmatic growl anywhere. It’s the sound of puberty, bad decisions, and a very specific brand of Netflix-funded anxiety. When we talk about Big Mouth voice actors, we aren’t just talking about people standing in a booth reading lines. We’re talking about a massive, revolving door of comedic geniuses who have essentially mapped out the internal plumbing of the human psyche—and then made it incredibly gross.
Nick Kroll is everywhere. Seriously. He isn't just the co-creator; he’s the lungs behind Nick Birch, Maurice the Hormone Monster, Coach Steve, Rick the Hormone Monster, Lola Ugfuglio Skumpy, and about a dozen other side characters that pop up to ruin someone's day. It’s a lot. Honestly, it’s impressive his vocal cords haven't just gone on strike yet. But while Kroll is the anchor, the show's staying power comes from how it handles its cast—sometimes with a bit of public turbulence.
The Big Switch: Why Missy’s Voice Changed
One of the most significant moments in the history of Big Mouth voice actors didn’t happen on screen. It happened on Instagram. For the first nearly four seasons, Jenny Slate voiced Missy Foreman-Greenwald. Slate is hilarious. She brought a very specific, nerdy vulnerability to the character that fans loved. However, in 2020, amidst a global conversation about racial representation in animation, Slate stepped down.
She argued that a Black character should be voiced by a Black actress. It wasn't a PR stunt; it was a fundamental shift in how the show approached its own "awkward-coming-of-age" mission statement. Enter Ayo Edebiri.
If you’ve seen The Bear, you know Edebiri is a powerhouse. But taking over Missy was a different kind of challenge. She didn't just mimic Slate; she evolved the character. By the end of Season 4, the transition was complete. Missy’s voice became slightly deeper, a bit more grounded, reflecting the character's own journey into discovering her Black identity and heritage. It’s one of the few times a mid-series recast felt like a narrative strength rather than a jarring distraction.
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Maya Rudolph is Carrying the Team
Let’s be real. Maya Rudolph as Connie the Hormone Monstress is the best part of the show. Period. The way she pronounces "bubble bath" (or bubbly bath) has basically become its own dialect. Rudolph brings a level of chaotic, maternal energy that shouldn't work but somehow defines the entire aesthetic of the series.
She’s won multiple Emmys for this role, and for good reason. Her performance highlights a specific nuance in the world of Big Mouth voice actors: the ability to be completely disgusting and deeply empathetic at the same time. When Connie is screaming at Jessi to steal a lipstick or hate her mom, there’s a weirdly protective layer underneath it. That’s not just writing; that’s Rudolph’s timing.
The Supporting Cast is Basically a Comedy Hall of Fame
John Mulaney voices Andrew Glouberman. It’s perfect casting because Mulaney’s natural "unfilled suit" energy fits Andrew’s perpetual state of horniness and shame. But then you look at the fringes of the cast.
- Jason Mantzoukas plays Jay Bilzerian. If you’ve ever heard Mantzoukas on a podcast, you know he only has one volume: Maximum. He plays Jay with a frantic, pillow-loving intensity that makes you worried for his actual health.
- Jordan Peele (yes, that Jordan Peele) was the Ghost of Duke Ellington. He also voiced various other roles before his directing career went into the stratosphere.
- Fred Armisen plays Elliot Birch, Nick’s over-sharing, "soft" dad. Armisen’s ability to be aggressively nice is genuinely unsettling.
- Jessie Klein isn't just Jessi Glaser; she’s a lead producer and writer. Her performance is the most "human" in a show filled with monsters.
Then there are the guest stars. Richard Kind as Marty Glouberman is a masterclass in "yelling as a personality trait." You’ve also got Jean Smart as the Depression Kitty, David Thewlis as the Shame Wizard, and even Thandiwe Newton as Mona the Hormone Monstress. The sheer density of talent is wild. It’s why the show can pivot from a joke about a sentient tampon to a devastatingly accurate depiction of clinical depression without losing the audience.
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The Hidden Labor of Voice Work
People think voice acting is easy. You show up in pajamas, yell for two hours, and go home. That’s not how Big Mouth voice actors operate. Because the show relies heavily on improvisation, the actors are often riffing with Kroll or the directors (like Andrew Goldberg or Mark Levin) for hours to find that one specific, weird joke that sticks.
Take the Shame Wizard. David Thewlis (Remus Lupin himself!) plays him with this oily, Shakespearian disdain. That’s a specific tonal choice that sets the stakes for the kids’ emotional trauma. If that voice isn't right, the character just feels like a bully. Instead, he feels like an inevitable force of nature.
The Controversy and Evolution of "The Hormone Monster"
The show has faced criticism. Some people hate the art style—they call it "ugly-cute" or just plain ugly. Others find the sexualization of middle schoolers to be a bridge too far. But the Big Mouth voice actors are the ones who bridge that gap. They play these roles with a "we've all been there" wink to the audience.
The introduction of the "Human Resources" spin-off further expanded this world, bringing in actors like Randall Park and Aidy Bryant. It proved that the vocal formula Kroll developed—mixing high-concept monsters with raw, embarrassing human emotion—had legs beyond the middle school setting.
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Why the Casting Matters for SEO and Beyond
When people search for who voices who in this show, they’re usually looking for that "Aha!" moment. "Wait, is the Ladybug really Seth Rogen?" (Yes, it is). The show thrives on that recognition. It uses our familiarity with these actors' "real" personas to subvert expectations. When you hear Andrew Rannells (a Broadway legend) singing about being a "bright-eyed, bushy-haired" kid, you're bringing his entire musical theater pedigree into a joke about puberty.
Navigating the Big Mouth Universe: Next Steps for Fans
If you're looking to dive deeper into the world these actors have built, don't just stop at the main series. The vocal performances evolve significantly if you watch the show chronologically alongside its spin-off.
- Watch the transition: Compare Season 3 Missy to Season 5 Missy. It’s a fascinating study in how two different actors can inhabit the same soul while bringing different cultural textures to the table.
- Listen for the "Kroll-overs": Try to spot every time Nick Kroll argues with himself. In some scenes, he is playing three different characters having a conversation. It’s a technical nightmare for sound editors but a showcase for his range.
- Check out Human Resources: If you want to see the Big Mouth voice actors lean into more "adult" themes (workplace burnout, grief, dementia), the spin-off gives actors like Maya Rudolph more room to breathe outside of the "school hallway" setting.
- Follow the creators' process: Many of these actors, specifically Kroll and Mulaney, have discussed their recording processes on various "Off Menu" or "Fly on the Wall" style podcasts. Hearing them talk about how they found the "voice" of a hormone monster provides a lot of context for the show's improvised feel.
The reality is that this show wouldn't work with "standard" voice actors. It needs the messy, idiosyncratic energy of stand-up comedians. It needs people who aren't afraid to sound disgusting. That’s what makes the cast of Big Mouth a singular force in modern animation—they’re willing to be as gross as we all felt when we were thirteen.
Practical Insight: If you're interested in the technical side of how these performances are captured, look up "ensemble recording" vs. "isolated recording." While most animation is recorded solo, the chemistry in Big Mouth often feels like the actors are in the room together, which is a testament to the editing team's ability to stitch disparate comedic riffs into a coherent, hilarious mess.