19 behind-the-scenes secrets you probably didn't know about 'Stranger Things'

Warning: Spoilers ahead for "Stranger Things."

For "Stranger Things" fans who can't get enough of the hit Netflix series, the streaming network has launched a new talk show hosted by Jim Rash called "Beyond Stranger Things." On the series, Rash is joined by cocreators The Duffer Brothers and executive producer Shawn Levy, along with a rotating set of the cast. 

Thanks to their conversations, plus interviews over the years, we've been able to roundup behind-the-scenes facts about the writing and production of the series.

Keep reading for a look at 19 things you probably didn't know about "Stranger Things."

SEE ALSO: 11 details you might have missed on 'Stranger Things' season 2

The Upside Down was called the Nether in every season one script and on set.

As The Duffer Brothers revealed on "Beyond Stranger Things," the Upside Down was referred to as the Nether in the original scripts and even on set during the first season's filming. 

But once series aired and fans honed in on the language used when Eleven and the boys flip over the Dungeons and Dragons board, the term Upside Down stuck.

The Demogorgon was a real guy in a giant suit for the first season.

While season two included plenty of special effects and CGI, the first season's Demogorgon was a man wearing a monster suit and small stilts and small amounts of green clothing so his real arms could be made invisible in the finished scenes.

Finn Wolfhard filmed his audition tape from his bed because he was so sick at the time.

On the first episode of "Beyond Stranger Things," host Jim Rash shares several clips of Finn Wolfhard (Mike), Gaten Matarazzo (Dustin), Caleb McLaghlin (Lucas) and Millie Bobby Brown (Eleven) auditioning for the series. 

Wolfhard's entire audition tape, recorded when he was just 11 years old, was filmed from his bedroom because he was really sick.