WARNING: This article contains spoilers for the second season of Stranger Things, streaming now on Netflix.
When Dustin is startled by a noise outside his house near the end of Stranger Things 2 Episode 2, it's a safe bet it's not the family cat prowling in the night, as he suspects, or even one of the Netflix drama's many allusions to E.T. the Extra-Terrestrial. This is Stranger Things, after all, where nothing good lurks in the shadows, and where curiosity -- among other things -- inevitably kills the cat. In the third episode, aptly titled "The Pollywog," Dustin discovers the culprit rattling around in the trash can and, to the audience's dismay, immediately adopts the slimy creature. But what is this pollywog?
It's a question that consumes first Dustin (played by Gaten Matarazzo), who's convinced he's made an important discovery, and then his circle of friends, which has expanded to include skateboarding new girl Max (Sadie Sink). But while Dustin sees in the pollywog an adorable 3 Musketeers-eating pet -- he names it D’Artagnan, or Dart for short -- and an opportunity for scientific fame, the others are far more skeptical. Undoubtedly because, well, they live in Hawkins, Indiana, and fought a freaking Demogorgon the year before.
However, Dustin is convinced Dart is a never-before-discovered terrestrial pollywog (that is, a tadpole that lives on land), but both the audience and Will Byers (Noah Schnapp) know better. While it's impossible to ignore the similarities to the 1984 comedy-horror classic Gremlins, in which a boy receives a cuddly little creature that's accompanied by a list of rules -- most pertinent here, don't expose it to sunlight -- there's the matter of those final moments of Stranger Things Season 1, in which Will, newly returned from the Upside Down, coughs up a slug-like creature in the bathroom sink as he experiences flashes of that shadowy mirror dimension.
Questions lingered about how much of that scene could be chalked up to hallucinations, part of the lingering trauma from Will's horrific experiences. But we now know it was all too real, because of the boy's deep-rooted connection to the Upside Down, and the terrors lurking within it.
As Dustin marvels at the pollywog, which he notes isn't an amphibian because it doesn't need water, and isn't a reptile, because it's warm-blooded, and his friends squirm -- "Ewwww, it's like a living booger!" Lucas proclaims -- Will is gripped by a creeping sense of recognition. When Dart coos and squeals, Will flashes back first to that moment in the bathroom and then to his most recent "episode," when he was surrounded by similar noises while trick-or-treating. He knows what Dart is, and so does the audience; it's a danger to all of them, even if Dustin refuses to recognize that. Will confides in his best friend Mike Wheeler (Finn Wolfhard), who sounds the alarm, just as the pollywog morphs before their eyes, growing larger, and growing legs, then leads the kids on a chase through the school.
Unwilling to kill his pet, Dustin finds Dart and secrets the creature away, returning it home to his bedroom aquarium. However, he soon regret the decision as the former pollywog grows to the size of a Cocker Spaniel, breaks through the glass and devours the family cat Mews. It's that act that finally turns Dustin against Dart, and leads to arguably the best team-up in Stranger Things history: Dustin and Steve Harrington (Joe Keery), Nancy's sometimes-boyfriend. Pressed by Steve about how he knows Dart isn't simply a lizard, Dustin responds, "Because his face opened up and he ate my cat!"