For a movie star with youth appeal so strong that it often feels like his comedies have been made by actual children, Adam Sandler has a mixed track record with family-friendly animation. His Hotel Transylvania series is popular, but their best moments spring from the sensibility of animator Genndy Tartakovsky more than the dads-gonna-dad Happy Madison humor. (Sandler apparently didn’t agree, leaving after the third movie in the series.) Left to his own devices in the animation world, Sandler has come up with stuff like the 2002 holiday cartoon Eight Crazy Nights, a flop that has all the toilet humor of his live-action films and none of their oddball charm. Maybe Sandler’s movies are juvenile enough that trying to do a kid-friendly version is an exercise in redundancy.

Nevertheless, the latest result of Sandler’s Netflix deal takes another shot at endearing the Sandman to kids who may not be quite old enough for Billy Madison’s antics. Sandler goes young by playing old: He affects a guttural squawk as Leonardo, a 74-year-old iguana who has been lazily serving as a fifth-grade class pet since the Truman administration. Alongside his de facto best friend, a turtle recently rechristened Squirtle (Bill Burr), Leo sits passively in his tank, watching as kid after kid passes through the final year of elementary school – until he realizes that he may be near the end of his lifespan and doesn’t have much to show for it. When the forbidding and unsmiling Mrs. Malkin (Cecily Strong) becomes the class’s long-term sub and insists on reviving the practice of sending the class pets home with students to teach them responsibility, Leo takes the opportunity to formulate an escape plan.

In the co-pilot’s seat for this routine-sounding mission is Robert Smigel, a former Saturday Night Live and Late Night with Conan O’Brien writer best known for creating material that only looks kid-appropriate, like his puppet character Triumph the Insult Comic Dog or his animated TV Funhouse segments on SNL. (A short-lived TV Funhouse series on Comedy Central went even further with puppet-hosted grotesquerie.) Smigel, Sandler, and Paul Sado wrote the movie together, with Smigel also credited as director alongside TV Funhouse vets David Wachtenheim and Robert Marianetti. The unremarkable, Illumination-ish character designs seem like the byproduct of Sandler attempting to ensure that he won’t receive further pushback from the likes of a Tartakovsky-level stylist.

On a writing level, Leo bucks a lot of familiar animation tropes. Rather than sending a sheltered lizard on a great-outdoors adventure and/or having him meet a special kid to bond with, the movie works its way into an appealingly clever structure: Each weekend, Leo goes home with a fifth-grader, attempts to escape, accidentally reveals that he can talk, and winds up offering some grown-up (maybe even downright grandfatherly) advice to kids who feel adrift in Mrs. Malkin’s newly strict classroom. It’s a neat and even surprising dynamic, punctuated by Smigel and company ribbing the formal rigidity of so many big-studio cartoons. When one kid’s family launches into a musical number – the film is a full musical, with half a dozen songs – the movie cuts away to another room, where the song can be heard continuing from the other side of the wall. The filmmakers are both conscious of and delightfully unconcerned with rules; the very fact of Leo’s talking isn’t governed by some kind of loophole explaining how people can understand him and why. He just keeps quiet around humans, noting that if word gets out about his ability to speak, they’ll “try to kill him, like E.T.”

The conceptual inventiveness should probably be expected of Smigel, who brought his satirical eye to You Don’t Mess with the Zohan and The Week Of, two of Sandler’s best comedies. But Leo, like The Week Of, also has a gentle, observational wit, which allows the movie to regard both kids and the act of raising them with a kind of skeptical affection – making fun of helicopter parenting through an overly attentive drone, or skewering familial entitlement with a life-lesson song about how nobody is all that great. At times, the movie is reminiscent of kid-centric episodes of classic Simpsons in its understanding of classroom quirks and accompanying ability to resonate with viewers of all ages.

Eventually, the movie becomes a barely disguised parable about the value of teachers, augmented by a comedian’s ego: Once again, Sandler plays a character who everyone in the movie adores, this time for his plainspoken wisdom. Yet the self-aggrandizement is easy enough to forgive, because the movie explicitly addresses that desire to be loved as part of Leo’s character arc. More implicit is the movie’s reflection on aging: Leo’s counseling of these kids on the cusp of adolescence maintains a bittersweet knowingness about the fleeting nature of childhood happiness. And if this all sounds a bit heavy for a family film, keep in mind that Leo is consistently silly and very funny – one of the best comedies of the year, animated or not. Sandler’s inner child and outer adult have rarely felt so well-synced.