Part of the appeal of animated series is that characters can remain the same age and exist in a place of stasis that’s impossible in live-action. Netflix’s Big Mouth, however, is one of the few animated series that allows its characters to actually grow older because these changes are fundamental to the types of stories it tells. Big Mouth’s characters are at a sensitive age where a year can feel like a lifetime.  This passage of time allows Big Mouth to feel fresh and gain a greater level of depth in its characters and storytelling, even if it’s still an absurdist comedy that frequently escapes into fantasy. Nick, Andrew, and Jessi’s development has always been the show’s focus, but their growth in season four is the most significant yet as these characters enter the eighth grade and sexual activity becomes a graspable reality rather than some impossible pipe dream. It allows season four to contain some of Big Mouth’s best and funniest moments and it instills confidence that the show’s upcoming seasons should be just as fulfilling as these characters clumsily stumble through adolescence and trudge through the remnants of puberty. Big Mouth season 4 begins with an entertaining change of pace where the unique stresses and joys of summer camp are experienced before the characters plummet into eighth grade. There’s a sunny atmosphere around these episodes, but there’s also a new sense of dread that begins to grow as characters move into more mature territory and become sex adjacent in their relationships. Summer camp is a really strong framing device and there’s just enough of it featured to feel satisfied, whereas an entire season that’s set at camp wouldn’t be able to sustain itself.  Big Mouth is often incredibly crass, but it’s also one of the most progressive and inclusive series on television. This season continues to tell important stories and there are episodes that maturely explore transgender representation, parents coming to terms with their children’s sexuality, and even code switching. It’s genuinely wonderful to see how Big Mouth represents something like gender transition therapy with its Hormone Monsters and the exaggerated rules that its world has established. It finds a creative way to visually explore the sensitive subject matter while still treating it all with respect. This allows these stories to get the same treatment as the other puberty stories the show presents. It makes them part of the norm rather than turn them into an anomaly in any capacity. This new season unpacks important topics in informative ways, like the use of tampons for the first time, an anthology installment based around “hand stuff,” and the loss of friends and social anxiety. However, certain episodes also take larger stylistic swings like one that jumps several decades into the future. Big Mouth is a balancing act that works because the show is simultaneously ridiculous as well as intensely realistic. The show is made for adults, but I’ve said in the past that children would actually benefit and learn from the stories being told in this show. That’s never been truer than now as these stories become more modern and universal with how they approach groups of people who haven’t previously been explored like this in animated series. It helps establish an important precedent that will hopefully be followed. Big Mouth excels with how it uses puberty as a filter to tell these hyperbolized stories, but even the show’s non-sequitur dialogue is gold. It’s rare that a show can be this genuine and thought-provoking while also being so absurdly laugh out loud funny. There’s also such satisfying and specific jokes for people who are inside baseball comedy nerds, like how these characters will be their voice actors’ pint-sized doppelgangers or literally quote lines from their stand up routines or podcast appearances. It’s not often that a character’s seemingly mundane name and design can generate laughs, but Big Mouth succeeds by knowing who their audience is and unabashedly playing into it. Season four plays with a lot of ideas, but it builds to an apocalyptic conclusion that’s all about learning how to embrace the worst parts of ourselves. It’s a valuable lesson, but its execution comes across as a little strained, in particular with Nick, but it’s still a satisfying season that’s able to bring all of its themes together. In doing so, Big Mouth’s fourth season pushes its characters further into adulthood and turns puberty and sex into less of a mystery.  As this process continues it’s understandable to consider how long Big Mouth can last after these characters enter high school, engage in more sexual activity, and stop being children. I fully expect the show will relish the opportunity to explore how these characters lose their virginities, just as it doesn’t belittle the significance of encountering genitals of the opposite sex for the first time this season, but it’s hard to imagine imaginary monsters following them around for long after that.  Much like puberty itself, certain moments of Big Mouth’s fourth season are awkward and messy, while others are sublime and unforgettable, but they all set up a promising future that can’t get here soon enough.