Character Leah Birch
Created by Nick Kroll, Andrew Goldberg, Mark Levin, Jennifer Flackett
Other cast Nick Kroll, John Mulaney, Jessi Klein, Jason Mantzoukas
Episodes S02E03, S03E03
Running time 30 minutes

VIDEOS

Big Mouth is an American adult animated sitcom created by Nick Kroll, Andrew Goldberg, Mark Levin, and Jennifer Flackett featuring teens based on Kroll and Goldberg’s upbringing in suburban New York, with Kroll voicing his fictional younger self.

Kat played the recurrent role of Leah Birch from seasons 1 to 4. In season 5, she was replaced with the voice talent of Chloe Fineman, as fans learned when the series was released and no sooner. The reasons for this change remain unknown.

Episode guide

Season 1

Episode 3: Am I Gay? A trailer for a new movie starring The Rock leaves Andrew questioning his sexuality. Jessi and Nick’s budding romance turns ugly fast.

Episode 5: Girls Are Horny Too A steamy novel making the rounds at school inspires Jessi to explore her own sexuality — and leaves the boys totally confused about what girls want.

Episode 8: The Head Push When Leah hosts a party for the high school drama crowd, Nick wrestles with a romantic dilemma; Andrew and Missy witness a disturbing scene.

Episode 9: I Survived Jessi’s Bat Mitzvah Jessi’s bat mitzvah brings out a lot of drama in her family, specifically pertaining to her mom and dad’s relationship. Nick wants to stop being treated like a baby. Andrew and Missy’s parents force them to stop dating.

Season 2 and special

Episode 2: What Is It About Boobs? A classmate’s booming bosom sends the boys into a rapture – and leaves the girls with a raging case of insecurity. Coach Steve drops a bombshell.

Episode 3: The Shame Wizard As Nick tries to figure out whether he has a shot with Gina, a mortifying encounter with Leah sends Andrew into a spiral of shame.

Episode 5: The Planned Parenthood Show An argument in sex ed class turns into a skit-tastic journey through the worlds of Planned Parenthood, contraceptives and STDs.

Episode 10: The Department of Puberty Nick finds a magic portal in his closet that had been left open by Tyler when he comes to inform Nick that he’s been fired from his job working as his Hormone Monster. Nick, Jessi, and Andrew travel through the portal to Puberty Headquarters, Nick seeks out a new Hormone Monster and Jessi bonds with the Depression Kitty. Maurice is troubled because he has to round up Nick, Jessi, and Andrew because if they spend more than an hour in the monster world then they will be either stuck as they are in puberty or they will become vein-y little child wrestlers. In the end of the episode we discover that Nick’s new hormone monster is Connie the Hormone Monstress and that he is Connie’s first boy. Jessi also escapes the clutches of the Depression Kitty and is returned to Connie.

My Furry Valentine is a special double-length Valentine’s Day episode of Big Mouth. It is in-between the second and third season. Sappy cards. Stupid clichés. And so much pressure. For Andrew, Nick, Jessi and friends, Valentine’s Day is a total freaking minefield.

Season 3

Episode 1: Girls Are Angry Too When a shop class mishap inspires a sexist dress code, Jessi rebels, Missy struggles to keep up her alter ego in check, and Andrew gets a wake-up call.

Episode 2: Cellsea Nick is bewitched by his cool new phone. A call from “Pharmacy Boy” turns Matthew into a nervous wreck. Jay finds a Netflix show made just for him.

Episode 5: How to Have an Orgasm Connie gives Jessi a crash course in female pleasure, Maury tries to talk Andrew into sending a dick pic and Nick lashes out at his new housemate.

Episode 7: Rankings As the friends feverishly swap lists of the hottest kids in school, newcomer Ali stokes the flames by announcing she’s pansexual.