Big Mouth’s Voice Actors: The Talented Cast Behind the Show’s Characters

Big Mouth isn’t your average cartoon. It’s awkward and eccentric, and it knows it.

Set in the chaotic world of seventh graders like Nick Birch and Andrew Glouberman at Bridgeton Middle School, the show is all about the messy time that puberty actually is. From shame wizards and anxiety mosquitoes to intense hormone monsters and even a talking couch cushion, Big Mouth is the imaginary world that every teen lives in.

But what really makes Big Mouth realistic is its voice actors. Behind every weird creature or confused teen is someone delivering the lines with brutal honesty and sharp comedy. These are more than just voices, they’re full-fledged performances.

From a Saturday Night Live writer playing multiple roles to other familiar voices like John Mulaney and Maya Rudolph, the cast balances chaos with skill. Their voice work makes the jokes land, giving depth to the wildest characters like Connie the Hormone Monstress, Depression Kitty, and shame wizard, the hormone monster's mortal enemy.

All in all, the voice cast expertly turns puberty’s worst moments into something funny, sad, and weirdly comforting.

In this article, we’ll take a look at the voice actors that make the magic happen on Big Mouth and a wonder tool that can help anyone recreate that magic from their home. We’ll also discuss Murf AI, a powerful tool to harness when you want to create life-like, realistic sounding voiceovers without the need of voice actors.

Big Mouth Voice Actors and Character Spotlight

Here are some of the most memorable Big Mouth characters and the voices behind the spoken words.

1. Nick Birch

Voice Actor: Nick Kroll

Character Spotlight: Nick Birch is confused, restless, and deeply uncomfortable in his skin, which is basically the whole point of the show. He gets stuck between childhood and puberty, and even talks to a couch cushion. His hormone monster is wild, and his identity crisis just keeps growing.

About Nick Kroll: Nick Kroll is a Saturday Night Live writer and the co-creator of Big Mouth. He’s also known for Kroll Show and Human Resources. His background in Comedy Central projects lets him flip voices easily, from boy band wannabes to anthropomorphic purple cats. Kroll also voices other characters like Andrew’s immature hormone monster Maury, Coach Steve, Rick the Hormone Monster, Lola Ugfuglio Skumpy, Nick Starr, and more.

2. Jessi Glaser

Voice Actor: Jessi Klein

Character Spotlight: Jessi is the smart, sarcastic realist of the group. She’s angry, messy, and often stuck between wanting to grow up and wanting to disappear. Her parents’ divorce, battles with Depression Kitty, and friendship fallout with Missy Foreman Greenwald take a toll on her. For better or worse, her hormone monster, Connie, and Tito Taylor Thomas, the anxiety mosquito are always buzzing.

About Jessi Klein: Jessi Klein is a comedian, author, and former head writer for Inside Amy Schumer. She’s also worked as a writer for Saturday Night Live. Her sharp writing background shapes her voice performance: smart but tired, cutting but kind. In Big Mouth, Klein draws from her personal experiences growing up. She makes Jessi feel like that one friend who pretends she’s fine, even when she’s not.

3. Missy Foreman-Greenwald

Voice Actors: Jenny Slate (Seasons 1–4), Ayo Edebiri (Seasons 4-8)

Character Spotlight: Missy starts off bookish and sweet, obsessed with facts and her stuffed toy. But she changes. She comes from a progressive and liberal household. As a result, she faces identity struggles and racial tension, but has a sound understanding of her body and sexuality, even beyond that of her peers.  

About the Voice Actors: Jenny Slate, a former Saturday Night Live cast member, voiced Missy early on. Her work includes notable roles in The Lorax, Zootopia, The Secret Life of Pets, and the Oscar-nominated Marcel the Shell with Shoes On. She left the role to make space for Black voice actor, Ayo Edebiri. Rising star Edebiri is famous for her role in The Bear, for which she’s won a Primetime Emmy and a Golden Globe. Her rendition of Missy has won praise for its authenticity and emotional depth.

4. Andrew Glouberman

Voice Actor: John Mulaney

Character Spotlight: Andrew is anxious, moody, and obsessed with girls. With Maury as his hormone monster, he’s the king of overthinking and shame spirals. Andrew’s late grandfather keeps showing up. But, he fails the rice purity test, and fights with everyone, including Nick. He’s fast, tense, and always close to a meltdown. Despite everything, he can manage his feelings, and demonstrate intelligence and empathy when required.

About John Mulaney: Mulaney is a stand-up comic and writer for Saturday Night Live, for which he has earned eight Primetime Emmy nominations. His dry humor and sharp timing make Andrew relatable. He’s known for voicing Spider-Ham in Spider-Man: Into the Spider-Verse, Chip in Chip n’ Dale, and Jack Horner in Puss in Boots: The Last Wish. On Big Mouth, he takes Andrew from gross to heartbroken to hilarious, all in one breath.

5. Jay Bilzerian

Voice Actor: Jason Mantzoukas

Character Spotlight: Jay is loud, chaotic, and wildly inappropriate. He’s obsessed with magic, Megan Thee Stallion, and sometimes his own pillow, Pam (or Pillow Jay). But he also deals with real neglect, especially from his mom. Jay’s journey from walking hormone to someone with real pain is shaped by Jason Mantzoukas’s frantic, heartbreaking delivery.

About Jason Mantzoukas: Mantzoukas is known for wild characters in Brooklyn Nine-Nine, The Good Place, and Parks and Recreation. However, he’s most recognized for his tones from The League, where he played Rafi. He brings high energy and chaos in his roles with ease. His voice acting in Big Mouth shows range, making Jay both disgusting and loveable. His timing turns even awkward silence into comedy.

6. Connie, the Hormone Monstress

Voice Actor: Maya Rudolph

Character Spotlight: Connie is power, passion, and perfume. She’s dramatic and pushes kids toward chaos. She influences Jessi and the other girls into yearning for vanity and expressing their sensuality. But she also has feelings. From guiding Missy and Jessi to fighting with her twin sister, Connie’s evolution is palpable. She seems to have a love-hate relationship with Maury, Andrew’s Hormone Monster.

About Maya Rudolph: Rudolph is an Emmy-winning actress and Saturday Night Live alum. She has a background in sketch comedy and music. Besides Connie, she voices Nick’s mother, Diane Birch and Bonrad “Bonnie” LaCienega, Connie’s twin sister on the show. Apart from that, she’s the voice behind Grace, an uptight anthropomorphic blue hippopotamus in Human Resources. Her other work includes movies like Bridesmaids, Away We Go, and The Way Way Back. 

7. Matthew McDell

Voice Actor: Andrew Rannells

Character Spotlight: Matthew is sharp-tongued, stylish, and the only openly gay character in the cast. He hides his emotions under sarcasm, but he wants love. He’s a student at Temple Beth Amphetamine, a Jewish synagogue and a prominent location in the show. His story touches on his relationship with his mom, coming out, loneliness, and faith. Jay Bilzerian and Aiden (known as Pharmacy Boy) are Matthew’s ex-boyfriends. Rannells gives him a calm, cool voice that breaks during the big emotional moments.

About Andrew Rannells: Rannells made his name in The Book of Mormon and Girls. He brings stage presence to every role, including his characters in Human Resources. His film career includes Don’t Understand You, A Simple Favor, and The Intern, and many more. 

8. Depression Kitty

Voice Actor: Jean Smart

Character Spotlight: Depression Kitty is calm, smooth, and terrifying. She shows up quietly and drags characters into sadness, especially Jessi. Her voice is slow, almost hypnotic, like she’s lulling you into giving up. She works in puberty’s Depression Ward with the Hate Worm and Shame Wizard.

About Jean Smart: Smart is a TV legend, known for roles in Hacks, Watchmen, and Frasier. She’s won multiple Emmys. Her performance as the anthropomorphic purple cat in Big Mouth is lowkey one of the show’s best. She doesn’t scream, but whispers, and that hits harder.

Other noteworthy characters and voice actors on Big Mouth include Elliot Birch voiced by Fred Armisen, Marty Glouberman voiced by Richard Kind, Devin LeSeven voiced by June Diane Raphael, Kenyan Shame Wizard voiced by Lupita Nyong'o, Mr. Keating voiced by Adam Scott, Monica Foreman Greenwald voiced by Chelsea Peretti, Gina Alvarez voiced by Gina Rodriguez, Simon Sex (a shroom-taking Hormone Monster) voiced by Jermiane Clement, queer lovebug Walter voiced by Brandon Kyle Goodman, couch cushion voiced by Gil Ozeri, and the Ghost of Duke Ellington voiced by Jordan Peele.

Big Mouth Behind-the-Scenes: Voice Acting Process

The cast of Big Mouth doesn’t just mouth lines, they become their characters. Behind the mic, it’s chaos, improv, and a lot of sweating in soundproof booths.

Nick Kroll records half the cast by himself: Nick Birch, Coach Steve, and more. In an interview with GQ, he said, “I’ll be yelling as Maury and then flipping to Nick crying about something his grandpa Andrew said—it’s a workout.”

Jenny Slate, who originally voiced Missy’s stuffed toy-loving self, talked about the emotional weight of voice work: “You’re sitting there alone in a booth trying to sob convincingly. It’s like acting without the costume.”

When Ayo Edebiri took over as Missy, the writers adjusted the tone. Her Missy explored racial identity, family dynamics, and deepest shame. In her own words, “They didn’t want me to just imitate Jenny. They wanted the new Missy to grow up.”

The voice sessions aren’t always solo. Sometimes actors riff off each other. Jason Mantzoukas and Andrew Rannells have recorded scenes together, especially ones involving shouting matches, wild hookups, or just Matthew roasting Jay’s mom.

Directors play a big part. They’ll pause takes to get the tiniest sound right. Crying, fighting, or a whisper from the hate worm, it’s all crafted. One of the directors described it as, “Like puppeteering with voices. You’re pulling emotions from sound alone.”

There’s also a ton of improvisation. Maya Rudolph, who plays Connie the hormone monstress, once made up an entire rant about Temple Beth Amphetamine in the booth. They kept it in.

You’ll hear voices shift in real time, from seventh grader Nick to the talking toad to Connie coaching puberty’s Depression Ward. There’s nothing smooth about it, it’s messy, real, and sometimes hilarious. And the right character voice generator will enable you to do it too, from the comfort of your home!

Explore AI-Powered Dubbing with Murf

Ever imagined giving Big Mouth characters like Nick Birch or Andrew's Irish accented lovebug your own twist? With Murf Dub, you can craft voiceovers that echo the show’s unique style.

While Murf doesn’t offer exact voice replicas, it equips you with the tools to create similar-sounding voices, perfect for fan content or creative projects.

Murf Dub supports over 20 languages and offers 200+ AI voices, allowing you to experiment with different accents and tones. Additionally, features like custom pronunciation control and pitch adjustment help you fine-tune your creations.

Whether you’re trying AI dubbing for cartoon characters, reimagining scenes with Jay Bilzerian or Nick's immature hormone monster, or crafting new dialogues for Missy Foreman Greenwald, Murf can help make the process intuitive.

For those looking to delve deeper, Murf’s voice cloning feature lets you develop unique voice profiles, adding depth to your projects. It’s a tool that brings your Big Mouth fanfiction or parody scenes to life, offering a platform to explore your creativity.

Interested in AI Dubbing for Your Animated Show? Get Started Now!