'Stranger Things' season 2 spoilers: The Upside Down will be revisited; Demogorgon in Will's body?

Promotional Photo for "Stranger Things"Facebook/StrangerThingsTV

In season 1 of "Stranger Things," the little town of Hawkins discovered an alternate dimension: a dark and creepy one called The Upside Down that will be explored more in season 2. Meanwhile, Will (Noah Schnapp) has returned from The Upside Down but it seems that not all is well with the child who came back from the brink of death.

In an interview, series creators and brothers Matt and Ross Duffer told Entertainment Weekly that  only a little bit of The Upside Down was revealed in "Stranger Things" season 1. The Duffer brothers agree that there is a big mystery left to explore in that alternate dimension.

"We obviously have this gate to another dimension, which is still very much open in the town of Hawkins. And a lot of questions there in terms of, if the Monster is dead, was it a singular monster? What else could be out there?" Ross said.

Another mystery to be solved in the upcoming season of "Stranger Things" is the fact that Will was coughing up what appears to be a huge slug-like creature. The sixth episode of season 2 from the Netflix announcement is titled "The Pollywog," which allegedly refers to the slugs residing in Will's body.

The Pollywog can be related to the "bullywug," a fictional monster with a frog-like human form from "Dungeons & Dragons," the game that Mike (Finn Wolfhard) and his friends always play. It is also the same game that helped them come up with the name "The Upside Down" for the alternate dimension located in Hawkins.

It is possible that the "Pollywogs" inside Will are Demogorgons in the larval stage, and that they are using his body as a host.

Initially, the Duffer brothers wanted to start "Stranger Things" season 2 with a time jump of a decade. However, because season 1 left many mysteries unsolved, specifically about the aftermath of The Upside Down opening, season 2 will kick off a year after the previous events, producer and director Shawn Levy told Slashfilm.

Levy teases that fans can expect "next-level, crazy stuff" to happen in season 2.

"Stranger Things" season 2 premieres in 2017 on Netflix.