Honestly, it’s kinda wild when you think about it. Most adult animation relies on a handful of "voices" to carry the weight, but the voice actors from Big Mouth are doing something much more complicated than just making funny sounds. They’re basically performing public therapy sessions while screaming about puberty.
Nick Kroll is the engine. He isn’t just voicing one kid; he’s essentially the architect of this entire hormonal universe. If you close your eyes, you can hear the slight overlap between Nick Birch and Maurice the Hormone Monster, yet they feel like entirely different entities. One is a neurotic, late-blooming pre-teen, and the other is a furry, hyper-sexualized manifestation of male impulse. That range isn't just a gimmick. It’s the reason the show survived its first season. Without that specific vocal chemistry, the gross-out humor would’ve felt cheap. Instead, it feels strangely human.
The Evolution of the Voice Actors from Big Mouth
The show didn’t just start with a bang; it grew into its skin. You’ve probably noticed that some characters sound different than they did in 2017. That’s because the show actually listened to its audience.
One of the most significant shifts in the history of the voice actors from Big Mouth involves the character of Missy. Originally voiced by Jenny Slate, the role was eventually transitioned to Ayo Edebiri. Slate herself initiated the change, acknowledging that a Black character should be voiced by a Black actor. It wasn't just a "woke" PR move; it actually changed the texture of the character. Edebiri brought a specific, awkward nerdiness to Missy that felt authentic to the character’s burgeoning identity.
Then you have Maya Rudolph. Is there anyone else who could make the word "bubble bath" sound like a four-course meal and a threat at the same time? Connie the Hormone Monstress is arguably the best-voiced character in modern animation. Rudolph’s performance is a masterclass in vocal gymnastics. She goes from a guttural growl to a high-pitched squeal in a single sentence, perfectly capturing the chaotic emotional swings of a teenage girl.
John Mulaney and the Power of the "Straight Man"
John Mulaney voices Andrew Glouberman. Mulaney’s voice is iconic—it’s that "old-timey radio announcer" vibe mixed with a 13-year-old’s desperation. In the world of the voice actors from Big Mouth, Mulaney acts as the anchor. While Nick Kroll is bouncing off the walls playing five different characters, Mulaney’s delivery is often dry, rhythmic, and incredibly precise.
His chemistry with Kroll is real. They’ve been friends since college (Georgetown, if you’re keeping track), and you can tell. The timing of their banter isn't just scripted; it’s the result of decades of improv. When Andrew is panicking about a "shame spiral," Mulaney’s voice cracks in a way that feels painfully relatable. It’s not just a cartoon. It’s a memory of being the most awkward person in the room.
👉 See also: America's Got Talent Transformation: Why the Show Looks So Different in 2026
The Supporting Cast You Probably Recognize
The bench is deep. Really deep.
- Jason Mantzoukas: He plays Jay Bilzerian. If you’ve seen The Good Place or Brooklyn Nine-Nine, you know his energy. He brings a frantic, unhinged quality to Jay that makes you wonder if Jason is actually okay. He isn't just yelling; he's projecting a specific kind of neglected-child-energy that makes Jay surprisingly sympathetic.
- Jordan Peele: Before he was winning Oscars for Get Out, he was the Ghost of Duke Ellington. His vocal range is staggering. He brings a soulful, weary wisdom to a character who is, quite literally, a dead jazz musician living in an attic.
- Fred Armisen: As Elliot Birch, Nick’s oversharing, "I love my son" father, Armisen uses a soft, breathless tone that is both heartwarming and deeply uncomfortable. It’s the ultimate "dad" voice.
Why the Casting Matters More Than the Script
You can write a funny joke about puberty, but if the delivery is off, it’s just a "dirty" joke. The voice actors from Big Mouth elevate the material into something that feels like a collective catharsis.
Take Andrew Rannells, for example. He plays Matthew, the school’s gay lead. Rannells is a Broadway veteran (The Book of Mormon), and he brings a theatrical sharpness to Matthew. His delivery is biting, but underneath the sarcasm, there’s a vulnerability that Rannells captures through subtle shifts in pitch. He makes Matthew feel like a real person navigating a difficult social landscape, not just a trope.
Then there’s the "Monsters" themselves. The show has expanded to include:
- The Shame Wizard (David Thewlis): A spindly, British-accented personification of self-loathing. Thewlis makes him sound elegant yet repulsive.
- The Depression Kitty (Jean Smart): Her voice is like velvet—heavy, suffocating, and strangely comforting.
- The Logic Rock (Chris O'Dowd): He brings a dry, Irish pragmatism that clashes perfectly with the emotional chaos of the other monsters.
These aren't just guest spots. They are tonal shifts.
The Controversy and Correction of Missy’s Voice
We have to talk about the Missy situation because it’s a pivot point for the industry. When Jenny Slate stepped down, it sparked a massive conversation about representation in voice acting.
✨ Don't miss: All I Watch for Christmas: What You’re Missing About the TBS Holiday Tradition
Slate was great. Nobody denies that. But Ayo Edebiri brought a different perspective. Because Edebiri is a writer and comedian who understands that specific intersection of "nerdy Black girl" culture, her performance felt lived-in. When Missy started exploring her hair and her heritage in later seasons, the voice felt like it was growing with the character. It’s a rare example of a casting change making a show better rather than just being a lateral move.
Behind the Scenes: How They Record
Most people think voice actors sit in a room together and riff. Usually, that’s a lie. Most animation is recorded solo because of scheduling.
However, the voice actors from Big Mouth often try to record together when possible—or at least they did in the early days. Kroll and Mulaney’s rapport is so central to the show that their sessions often involve a lot of "off-book" riffing. This is why the dialogue feels so fast. It’s not just lines on a page; it’s a conversation.
The production team, including Mark Levin and Jennifer Flackett, encourages this. They want the actors to find the "ugly" parts of the performance. If a voice cracks or someone stumbles over a word because they’re laughing, it often stays in. That’s the "human" quality that makes the show stand out in a sea of overly polished content.
What Most People Miss About the Voice Work
The subtle genius of the show is how the actors differentiate between the "human" world and the "monster" world.
When Nick Kroll plays Nick Birch, he’s constricted. He sounds small. When he plays Maury, he’s expansive. He uses his full diaphragm. This contrast creates a psychological map for the viewer. We know when we’re in a character's head and when we’re watching them interact with the "real" world.
🔗 Read more: Al Pacino Angels in America: Why His Roy Cohn Still Terrifies Us
Maya Rudolph does the same. Her Connie is huge, but when she voices other minor characters, she dials it back. This isn't just "doing voices." This is character acting. It requires an understanding of the emotional beat of the scene. If Connie is being supportive, her voice gets a raspy, maternal warmth. If she’s being destructive, it becomes a sharp, jagged edge.
Essential Insights for Fans and Aspiring VOs
If you’re looking at the voice actors from Big Mouth as a template for how to get into the industry, there are a few things to keep in mind.
First, these people are comedians first. They aren't just "voice guys." They are people who understand timing, subtext, and character arcs. The industry is moving away from the "guy with a deep voice" toward actors who can bring a specific point of view to a role.
Second, the show proves that "ugly" is better than "perfect." The most popular characters are the ones who sound the most flawed. Whether it’s the wet, slapping sounds of the Hormone Monsters or the screeching anxiety of the kids, the "texture" of the sound is what sticks with you.
To really appreciate the craft, try these next steps:
- Listen for the "Doubling": Watch an episode and try to identify every character Nick Kroll plays in a single scene. It’s usually more than you think (he voices over 30 characters across the series).
- Compare Spin-offs: Check out Human Resources. It’s a spin-off that focuses entirely on the creatures. You’ll see how the voice actors have to carry the emotional weight without the "human" anchors.
- Watch Ayo’s Transition: Re-watch the end of Season 4. You can actually hear the moment where the voice changes. It’s handled with a lot of grace and meta-humor.
- Check the Guest List: Look up the credits for minor characters. You’ll find everyone from Richard Kind to Kristen Wiig. The show is a "who's who" of comedic talent for a reason.
The voice actors from Big Mouth have created a new standard for adult animation. It’s not just about being shock-value funny; it’s about being honest. That honesty starts in the recording booth.