You probably recognize that raspy, hormone-addled screech from anywhere. It’s the sound of awkwardness. When you first watch Big Mouth on Netflix, the sheer volume of voices coming out of the screen is overwhelming. You’ve got puberty monsters, sentient hormone-driven pillows, and kids who sound just a little too much like middle-aged comedians. That’s because they basically are.
The primary Big Mouth voice actor you need to know about is Nick Kroll. He’s the engine. Kroll doesn't just voice one character; he’s essentially the entire ecosystem of the show. He voices Nick Birch, Maurice the Hormone Monster, Coach Steve, Lola, and Rick the Hormone Monster. Honestly, the man’s vocal cords must be made of industrial-grade leather to survive those Lola screaming matches.
The show is loosely based on Kroll’s actual childhood in Westchester County, New York, alongside his best friend Andrew Goldberg. If you ever wondered why the dynamic between the two leads feels so lived-in, it’s because it is literally a dramatization of their puberty-stricken friendship.
The duality of Nick Kroll and John Mulaney
Most people jump into the show for the crude jokes, but they stay for the chemistry. John Mulaney voices Andrew Glouberman. Mulaney’s delivery is distinct—stiff, anxious, and perpetually on the verge of a breakdown. It perfectly mirrors Andrew’s character, who is the "early bloomer" of the group.
There is a specific rhythm to how Kroll and Mulaney interact. They’ve been working together since their "Oh, Hello" days, and that shorthand carries the show. When Nick Birch is having a crisis, and Andrew is being a neurotic mess, it feels like a real conversation between two people who have known each other’s deepest, darkest secrets for thirty years. Because they have.
But the Big Mouth voice actor list isn't just a two-man show. It’s a massive ensemble that has shifted over time, sometimes due to controversy and sometimes just for the sake of the joke.
Maya Rudolph and the Hormone Monstress
If Nick Kroll is the engine, Maya Rudolph is the soul. She voices Connie the Hormone Monstress. Her performance is legendary at this point—specifically the way she says "bubble bath" or "nathaniel." It’s a masterclass in vocal manipulation. Rudolph brings a weirdly maternal yet chaotic energy to the role that makes Connie more than just a personification of estrogen; she’s a cultural icon.
💡 You might also like: Ashley My 600 Pound Life Now: What Really Happened to the Show’s Most Memorable Ashleys
Rudolph also voices Diane Birch (Nick’s mom), which creates this strange, subtle layer where the voice of the mother and the voice of the puberty monster are the same person. It’s a brilliant bit of casting that reflects how kids often project their parental figures onto their own internal development.
That huge Missy transition you noticed
Let’s talk about Jenny Slate and Ayo Edebiri. For the first few seasons, Jenny Slate was the Big Mouth voice actor for Missy Foreman-Roberts. Missy is a biracial character, and Slate, who is white, voiced her with a perfect, nerdy innocence.
In 2020, during the height of the Black Lives Matter movement and a broader cultural reckoning regarding voice acting, Slate stepped down. She publicly stated that her playing a Black character was an act of erasure. It wasn't a "cancellation" in the traditional sense; it was a voluntary exit to allow for more authentic representation.
Enter Ayo Edebiri.
Edebiri took over midway through Season 4. The writers didn't just swap the voice and hope nobody noticed. They baked the change into Missy’s character arc. As Missy began to explore her Black identity and embrace a more complex version of herself, her voice changed. It was one of the most graceful handoffs in animation history. Edebiri brought a grounded, slightly more mature tone to Missy that helped the character evolve from a "geeky kid" into a young woman finding her voice.
Why the guest stars feel so weirdly perfect
One of the best things about the show is how it utilizes celebrities for one-off gags. You’ve got Jordan Peele voicing the Ghost of Duke Ellington. Think about that for a second. One of the most important directors of our generation spent years voicing a ghost that lives in a teenager’s attic and gives terrible advice about girls.
📖 Related: Album Hopes and Fears: Why We Obsess Over Music That Doesn't Exist Yet
Then there is Jason Mantzoukas. He plays Jay Bilzerian. If you’ve seen The Good Place or Brooklyn Nine-Nine, you know Mantzoukas does "unhinged" better than anyone else on the planet. Jay is a character who is obsessed with magic and, well, pillows. Mantzoukas brings a frenetic, high-octane energy that makes Jay feel genuinely dangerous and lovable at the same time.
A quick look at the expanded roster:
- Fred Armisen: Elliot Birch (Nick’s overly affectionate dad). Armisen plays him with a soft-spoken creepiness that is hilariously uncomfortable.
- Jessi Klein: Jessi Glaser. Klein is a stand-up and writer, and she brings a dry, sarcastic wit to Jessi that makes her the most relatable character for anyone who hated middle school.
- Andrew Rannells: Matthew MacDell. Rannells is a Broadway star, and he gives Matthew a sharp, "Mean Girls" edge that eventually softens into a really beautiful coming-out story.
- Thandiwe Newton: Mona the Hormone Monstress. She provides the perfect foil to Connie, playing the "cool girl" version of a hormone monster with a sophisticated British accent.
The technical side of being a Big Mouth voice actor
Recording a show like this isn't just standing in a booth and reading lines. Because many of these actors are also writers and producers on the show, the sessions are highly improvisational.
Kroll has mentioned in several interviews that he often records "scratch tracks" where he tries out dozens of different voices before landing on the right one. Coach Steve, for instance, wasn't originally supposed to be such a massive part of the show. His voice—a sort of mush-mouthed, confused whisper—was so funny to the crew that they kept writing him into scenes until he became a series staple.
The recording process also changed during the pandemic. Like many shows, the actors had to set up home studios. This actually led to some interesting vocal textures in later seasons, as the intimacy of a home recording sometimes bled into the performances.
Is the show ending?
Yes. Netflix confirmed that Season 8 will be the final chapter. This makes Big Mouth the longest-running scripted series in Netflix history (excluding kids' programming). It’s a massive feat for an adult animation show that started as a "weird little project" about dicks and periods.
The longevity of the show is a testament to the Big Mouth voice actor cast. They managed to make characters who are objectively gross feel deeply human. You care about whether Nick and Andrew stay friends. You care about Jessi’s mental health. You even care about the Shame Wizard (voiced brilliantly by David Thewlis, who you might know as Remus Lupin from Harry Potter).
👉 See also: The Name of This Band Is Talking Heads: Why This Live Album Still Beats the Studio Records
Addressing the "Too Gross" criticism
Look, this show isn't for everyone. Some people find the voice acting too abrasive or the content too graphic. But if you look past the "Florida" jokes and the singing pubic hair, the voice acting is doing some heavy lifting regarding emotional intelligence.
Take the "Depression Kitty," voiced by Jean Smart. Her voice is seductive, low, and heavy. It perfectly encapsulates what depression feels like—not necessarily sadness, but a heavy, purple velvet blanket that makes you never want to leave your bed. That’s not just a funny voice; that’s a nuanced performance that helps people understand their own mental health.
The actors aren't just playing caricatures. They are playing the personification of internal struggles.
Key takeaways for fans and aspiring actors:
- Authenticity matters: The shift from Jenny Slate to Ayo Edebiri showed that animation is moving toward more responsible casting.
- Chemistry is king: The friendship between Kroll and Mulaney is the bedrock of the show’s success.
- Versatility wins: Nick Kroll playing five or six characters per episode is a masterclass in vocal range.
- Embrace the weird: Most of the best voices in the show came from improvising and making the producers laugh during recording sessions.
If you’re looking to dive deeper into the world of these actors, check out the spin-off Human Resources. It expands the "monster" world even further with voices like Hugh Jackman (as Dante the Addiction Angel) and Helen Mirren (as the Shame Wizard's mother). It’s essentially the same creative DNA but with the scale turned up to eleven.
To truly understand the impact of the Big Mouth voice actor ensemble, you have to watch the behind-the-scenes table reads. Seeing Nick Kroll flip between the raspy growl of Maury and the high-pitched whine of Lola in a matter of seconds is genuinely impressive. It’s a reminder that while the show looks like a cartoon, the performances are very much real, very much practiced, and very much the reason the show has lasted as long as it has.
Next Steps for You
If you want to track the evolution of these voices, start by re-watching the Season 4 transition of Missy. Pay close attention to the episode "A Very Special 9/11 Episode" where the vocal shift begins. It’s a landmark moment in modern animation. Also, if you’re into the technical side, look up Mark Rivers, the man responsible for the songs. The actors have to sing in character, which is a whole other level of difficulty—especially for Kroll when he’s singing as a Hormone Monster.
Stay tuned for the final season, as rumors suggest several legacy voice actors from Kroll's past sketches might make a "full circle" appearance before the kids finally (hopefully) graduate from middle school.