Big Mouth’s season 3 was packed with references to various films and TV shows, with the characters mostly making fun of these, as they did with one of the most recent versions of the Joker. Although Big Mouth mostly focuses on sexuality and puberty, the writers always find ways to mock as many pop culture products as they can, all as part of the series' satirical style and sometimes as part of their exploration of social issues.
Season 3 continued following Nick, Andrew, Jessi, Missy, Jay, and friends (as well as Coach Steve, of course) in their journeys through puberty and the struggles that come with it. This season also addressed topics like pansexuality (for which the writers were criticized), toxic masculinity, and incest. But Big Mouth also has some lighter moments that, while they also mock other media products and topics, are not as intense as, let’s say, Andrew making out with his cousin. Season 3’s finale is an example of this, with a bunch of references to many comic book characters, including Batman’s archenemy, the Joker – but not quite Joaquin Phoenix’s version.
Big Mouth’s season 3 finale, “Super Mouth”, sees the teens gaining superpowers as result of a freak storm – but it's later revealed that their superhero personas are all part of Caleb’s imagination as he tries to understand all the drama going on around him. Still, these superpowers and identities extended to characters outside school, such as Nick’s mom, who appears to Jay when he’s in need of motherly advice, and Jay’s brothers, Kurt and Val. Because these two have never been nice to anyone, they were portrayed as Batman villains: Kurt was Tom Hardy’s Bane, and Val was Jared Leto’s Joker. Aside from that riff, though, what's best is that comment from Kurt/Bane while Val/Joker looks on approvingly, as he says: "Society is our butt to f**k," a spin on the "We live in a society" meme that is closely linked to the Joker character, and has seen something of a rebirth with the Joker movie and its own comments about society, which comes pretty close to making the meme a movie quote.
It's not impossible that Big Mouth took a shot at Phoenix's Joker, since the movie has been in development for some time, but it's more likely aimed at the meme as a whole, while also riffing on Leto's Joker. It’s quite fitting that Val and Kurt were portrayed as villains as they both tend to be quite chaotic. Leto’s version of the Joker is arguably the most chaotic of all (and not exactly because of his actions), with many fans finding aspects of it to be off-character, and the overall performance (and role in the film) was pretty messy.
While in their villainous roles, Val and Kurt make Jay take an oath to become a “true Bilzerian” and place explosives in the bathrooms at the mini golf, but after Jay attacks Kurt when it becomes a giant monster made of crap, they tell him he’s not a Bilzerian. Val even laughs as Leto’s Joker, and doesn’t exactly do the dirty job himself, instead making Jay and Kurt do it.
With Big Mouth renewed through a sixth season, viewers can expect a lot more references to different pop culture figures in future seasons – and with superheroes still being a relevant (and profitable) topic in the entertainment industry, the series will surely continue to mock many more characters from those universes.