Mild spoilers for Stranger Things Season 2, Episodes 1-3 ahead. Will’s been through an awful lot on Stranger Things — he was taken hostage into the Upside Down by the Demogorgon in Season 1, and things haven’t exactly gotten better. At the end of Season 1, after Will was brought back into his right-side-up world in Hawkins, Indiana, things seemed fine… except for when he went to the bathroom and coughed up a slug. (I just gagged, too.) Flash forward to Season 2, when Dustin brought home a slimy little creature from his garbage can and named it like a pet. But, is Dart the slug that Will coughed up in Stranger Things Season 1? It certainly seems like both of these creatures are bad news.
Why Dustin would bring a creature like Dart into his house, I have no idea. It all started on Halloween night, 1984, after Dustin, Will, Mike, and Lucas go trick-or-treating. The boys split up because Will has an “episode,” as they’re calling them, into the Upside Down, and, upon returning home, Dustin hears something rattling in his garbage can. Then he brings it inside. (Oh boy.) It turns out that it’s some weird sort of reptilian slug creature that he names D’Artagnan (after the musketeer), or Dart for short. Putting Dart in a cage, he discovers that he doesn’t like bright lights but loves nougat. But after reading up on the subject of amphibians, Dustin thinks he discovered a new species, to which all of his friends are like, “Um, what?” They're concerned, as they should be, especially when Dart escapes in Hawkins Middle School. Dustin gets him back, only to hide him from his friends. This won’t end well.
Seriously, though — if you knew that you lived in a town that was a portal to another, eviler dimension, why would you take anything strange into your home and feed it Halloween candy? The correct answer is no. Anyway, Will, whose episodes have been getting increasingly more violent and paralyzing as Halloween has approached, seemingly knows exactly what Dart is — the slug that he threw up into his sink a year prior, and if Dart isn’t that exact slimy creature, he’s a slimy little creature that looks a lot like it.
What’s puzzling is that Will, for better or for worse (and probably worse), doesn’t come right out and say what Dustin's new pet is. He’s too scared, and even though Mike and Lucas try to talk some sense into Dustin, Dustin's not having it. And Dart is growing bigger by the minute, making him even more terrifying. Why are these kids not more afraid of this unknown creature? It’s pretty clear that Dart is something from the Upside Down, and nothing that has ever happened in the Upside Down has ever been good for the young cast of Stranger Things. (R.I.P. Barb.)
Speaking of Barb, whatever the slug means, it’s not good. When Barb died in the Upside Down, Will saw her corpse and a slug crawled out of her face. Will has returned back from the Upside Down, and he’s clearly a changed person. Nothing can go back to the way that it was, and Will seems to be the only one who recognizes that. Does Dart’s presence denote for Will a fate similar to Barb’s? Is Will marked to be taken into the Upside Down again? His episodes aren’t really psychiatric breaks — Will is experiencing the Upside Down, meaning that it never left him. In terms of what Will could cough up, there is a possibility that there are more slugs where that came from (so gross). Will’s friends will certainly fight to protect him, but Will has to admit what’s happening and figure out how to beat these slug things before they take over him completely.