Your Guide to the Celebrity Guest Voices of Big Mouth Season 4

Netflix's Big Mouth returns for its fourth season this week. Co-creators Nick Kroll and Andrew Goldberg are back with a season that takes our main characters from summer camp, to New York City, to the future and beyond. Oh, and they're entering 8th grade. Wild times ahead.

And as with any new season of Big Mouth, our attention turns to who's new and returning in the voice cast. The entire main cast is back, with one big asterisk: Jenny Slate exited her role as Missy late into the production of Season 4. Beginning with episode 9, Missy will be voiced by stand-up comedian and comedy writer Ayo Edebiri.

Also joining the show this season are a number of new characters, voiced by some wonderful and very familiar guest voice actors. Rather than have you agonize over whose voice you're hearing and struggling to place, we've put together this guide.

Seth Rogen as Seth Goldberg

The instantly recognizable voice of Seth Rogen shows up in the season premiere where he's voicing Seth Goldberg, Nick's longstanding friend from camp. Nick's "summer Andrew" comes along at a time when Nick and Andrew are on the outs (recall that Nick made a move on Andrew's ex Missy at the end of last season), so the dynamic at camp gets real awkward.

John Oliver as Harry

Another incredibly recognizable voice this season is Last Week Tonight host and former Daily Show correspondent John Oliver, who shows up as clueless camp counselor Harry. Oliver last lent his voice talents to an animated film in the 2019 remake of The Lion King, where he played Zazu.

Maria Bamford as Tito the Anxiety Mosquito

The show that previously brought us the Shame Wizard (voiced by David Thewlis), the Depression Kitty (voiced by Jean Smart), and numerous Hormone Monsters has upped the ante in Season 4 with the Anxiety Mosquito, buzzing around and giving the main characters plenty to feel self-conscious and miserable about. This skeeter is voiced by comedian Maria Bamford, who previously excelled on Netflix with her two-season autobiographical comedy Lady Dynamite.

Sterling K. Brown as Michaelangelo

The two-time Emmy winner for This Is Us and The People vs. O.J. Simpson joins Big Mouth this season as Michaelangelo, a hip and artistic new character who Jessi encounters in New York City, where she's gone to live with her mom.

Zach Galifianakis as The Gratitoad

The star of Baskets and the Hangover movies, Galifianakis joins the Big Mouth cast this season as a character called the Gratitoad, who is exactly what he sounds like: a toad who is very into expressing gratitude.

Josie Totah as Natalie

Josie Totah joins the cast as Natalie, a transgender summer camper whose storyline intersects with Jessi's. Totah previously starred on the NBC series Champions and the film Other People. She's currently starring on the rebooted Saved by the Bell.

Quinta Brunson and Lena Waithe as Quinta and Lena

Missy goes to visit her family in Atlanta, where she has to grapple with her own Blackness. Her cousins, Lena and Quinta, are voiced, appropriately enough, by Lena Waithe and Quinta Brunson. Waithe is the Emmy-winning writer and actress from Master of None and Ready Player One, and Brunson is one of the main cast members on the HBO sketch series A Black Lady Sketch Show.

Thandie Newton as Mona the Hormone Monstress

Newton actually made her Big Mouth debut at the very end of Season 3, showing up as Missy's long-awaited Hormone Monstress. But as is the case with a few other characters, including Tony-winner Julie White as Matthew's mom, Season 4 is where Mona really gets to show her stuff, pushing Missy to grow up, try new things, and express her anger.

Anna Konkle and Maya Erskine as Izzy and Misha

Konkle and Erskine are best known for creating and starring in the Hulu series PEN15, where the adult actresses play teenage versions of themselves in the late 1990s. The second season of that show dropped earlier this year, further cementing it as one of the best TV shows ever about adolescent awkwardness. In a nod to their own show on the topic, Big Mouth cast Konkle and Erskine as Izzy and Misha, two 7th grade girls who Nick and Andrew meet when the school year begins.

Paul Giamatti as I'm Not Telling You

Some things on Big Mouth are too much of a big, gross surprise to spoil, and one of them is the character Paul Giamatti voices this season. The Oscar-nominated actor is best known for films like Sideways and TV shows like Billions, and his distinctive raspy growl is on full display. Trust me, when you get to his character, you'll know it.

The fourth season of Big Mouth drops on Netflix December 4th.

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Joe Reid is the senior writer at Primetimer and co-host of the This Had Oscar Buzz podcast. His work has appeared in Decider, NPR, HuffPost, The Atlantic, Slate, Polygon, Vanity Fair, Vulture, The A.V. Club and more.