By episode three of its eighth and final season, Big Mouth is doubling down on what made it iconic in the first place: turning the chaos of adolescence into something hilariously relatable and emotionally profound. “Why Do We Go Through Puberty?” doesn’t merely ask the question. It takes us on a journey through it, literally.
Nick, who’s been in a perpetual state of short-kid blues since the show began, finally hits a milestone: a sudden growth spurt. It’s the kind of moment that’s both triumphant and terrifying. The writers use it as a narrative launchpad to explore deeper, messier questions about identity, body image, and change. The class, led by the delightfully odd Ms. Dunn, embarks on an imaginative field trip through the human body, a tour of hormones, awkward erections, and the wild world of adolescent biology. Think Magic School Bus with more testosterone and way less censorship.
And, in true Big Mouth fashion, the gross-out humor is backed by a deeper emotional current. Nick’s transformation is celebrated by his friends with a cringe-worthy surprise party. He’s playfully dubbed “Pubee Herman” and offered mock tributes to his growing armpit hair and cracking voice. But beneath the teasing lies genuine affection, this is how teenage boys say, “We see you. We’re with you.” This is the kind of moment Big Mouth does so well using absurdity to underline emotional truth.
Elsewhere, the in-body adventure becomes an allegory for internal confusion. As the class travels through organs and systems, they’re forced to confront how little control they have over the changes their bodies are undergoing. The show leans into the surreal here, featuring hormone monsters who cheerlead or criticize with hilarious flair. It reminds us that puberty is awkward, confusing, involuntary, and often isolating.
Animation-wise, the episode stays visually consistent with the show’s well-known exaggerated, expressive style. Every physical shift, whether it’s Nick’s new height or an animated pituitary gland is dramatized for comedic and narrative impact. It’s zany, yes, but also emotionally accurate. Adolescence feels exaggerated when you’re living it.
Performance-wise, the core voice cast remains in top form. Nick Kroll gives Nick’s panic a perfect pitch of confused enthusiasm, while John Mulaney’s Andrew provides grounding comic relief. Jessi Klein and Maya Rudolph bring an extra layer of sparkle balancing sass, sarcasm, and surprising wisdom. The show doesn’t just rely on punchlines, it leans into voice work to deliver vulnerability too.
More than anything, “Why Do We Go Through Puberty?” serves as a gentle affirmation that what we feel in our early teens—fear, confusion, hope is universal. It’s not a question the episode fully answers, and that’s the point. It isn’t about solving puberty but about making peace with it. The show reaffirms that being young, confused, and hormonal doesn’t mean you’re broken. It just means you’re human.
With only a handful of episodes left, Big Mouth is laying a strong emotional foundation for its exit. And while this episode is a celebration of Nick’s literal and metaphorical growth, it’s also a quiet salute to every viewer who’s ever wondered, “Am I the only one going through this?” Spoiler: you’re not.
