Some of the funniest behind-the-scenes moments from Stranger Things are almost as iconic as the show itself. The cast frequently share clips of themselves breaking character, especially Millie Bobby Brown, Finn Wolfhard, and Joe Keery. They didn’t even spare emotional scenes—Eddie’s last words or Hopper Joyce kiss in season 4, which was totally not planned. 

We have collected 5 such BTS moments that are fun, amusing, and interesting to watch and know.

Stranger Things scenes that had impromptu improvisations

1. The mind-flayer prop Is just a guy in a red suit

Many fans used to think that mind flayer is CGI made, but it’s actually not. The actual Mind-Flayer was played by someone in a red bodysuit with a shiny helmet. It’s wild how casting magic and visual effects turn that goofy costume into something terrifying. 

2. “I love you, man” – the last words from Eddie was totally not planned

Eddie’s last words to Dustin in the S4 finale (“I love you, man”) weren’t in the script. Joseph Quinn just blurted them out at the moment. That kind of raw, unplanned emotion hits differently. 

3. Lucas’ “Erica, help!” moment came from real desperation

When Lucas screams “Erica, help!” in the hospital room, that line wasn’t originally written. Caleb McLaughlin came up with it amidst the chaos of the scene — and it became one of the gut-wrenching highlights. Stranger Things writers actually shared this on X.

4. Hopper & Joyce’s kiss wasn’t scripted either

That reunion kiss between Hopper and Joyce in the Season 4 finale? The kiss between them wasn’t scripted — Winona Ryder and David Harbour added it in during filming. And it just felt right—massively emotional because it wasn’t planned. (Chapter Nine: The Piggyback).

Want to catch up? The kiss scene happens in the final episode of Season 4 Vol. 2. 

Or watch it here.

5. Eleven collapsing into Mike’s arms (S3, School Gym Sauna Battle)

After battling possessed Billy, Eleven is emotionally and physically exhausted. Millie Bobby Brown truly collapsed—unscripted—from the agony of that scene, and her collapse stayed. Mike looks shocked, then supports her. 

Fun Stranger Things BTS moments 

1. Cast arguing over chips like siblings

Millie Bobby Brown and Caleb McLaughlin shared that their off-camera relationship has devolved from being super nice to full sibling-rivalry — like fighting over who ate whose chips during the set. Felt so real. Source: Teen Vogue

2. Joe Keery & Gaten Matarazzo: staring contest + trust fall

In a Glamour interview, Steve (Joe) & Dustin (Gaten) spent four full minutes staring at each other, doing trust falls, and complimenting each other. It was supposed to be promotional but ended up super silly. Glamour

Both actors are unanimous when picking their favorite moment of the season: “The railroad scene!” they said in unison. “It was so much fun. “It was also the first time having almost three pages of dialogue.” – Joe Keery

3. Joseph Quinn’s demonstration with tennis balls vs demo bats

When filming Eddie’s big demo-bats rescue, they used tennis balls and sticks to mimic the bats. Joseph Quinn later said he “went crazy trying out dance moves” reacting to the silly stand-ins. EW.com

4. Vecna reciting romantic movie lines & Lizzo lyrics on Fallon

Jamie Campbell Bower (Vecna) recited lines from Notting Hill, Titanic, and Lizzo songs — all in Vecna’s creepy voice. He said he practiced in weird ways (walking around “nearly naked”) to get the voice right. It’s creepy + hilarious. 

Sharing the Instagram reel here: https://www.instagram.com/reel/Cg2z8svDhGt/ 

5. “So many giggles” during hospital-scene breaks

Sadie Sink, Millie Bobby Brown, and Noah Schnapp had lots of off-camera laughter between takes during the hospital scenes. Even though the in-scene energy was heavy, behind the scenes they were goofing and joking. Even Millie Brown shared this on her Instagram as well.

Other BTS tweets, reels, and posts from Stranger Things cast and crew

What is it about?Link to peep into it
Eddie strumming guitar, practising to do it for one last time 😭 https://x.com/strangerwriters/status/1546144270255538178?ref_src=twsrc%5Etfw%7Ctwcamp%5Etweetembed%7Ctwterm%5E1546144270255538178%7Ctwgr%5Ea3dc0e42161c30ed4e956bd4812e6145df503c22%7Ctwcon%5Es1
Stranger Things set tour from the cast (right after season 1 was shot).https://www.youtube.com/watch?v=1DTxO9tW2p4 
Max being dragged on floor in the Upside Down world btshttps://dnm.nflximg.net/api/v6/2DuQlx0fM4wd1nzqm5BFBi6ILa8/AAAAQT9-6r4_aN_AOjD_zSwRTLN-GB5EKqv5E2ZZBE9zRGBIHQVm_T2KOaAx_dHOCiaf9rDVxUi_QZfjsTUrlZhhcdYt11zeEl8vVmepGMD4nIzT0wAiZYHR009LdHCyW7iq6ASapImiBjU2yCpvmyu1MMb6.jpg?r=479 
Max and Will being best buds forever—one lying their head on the other’s shoulderhttps://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcRzGrXUtPTa3UkVJLwA7ZJhhI7fXEjIVAdQHQ&s 
Someone actually made real-life size Max floating DIY for a scary Halloween makeover. What’s surprising is that they spent ~1,500 hours decorating their home with this setup.https://www.youtube.com/watch?v=FwzkEnthXq8 
Grace Vandien on Instagram dancing around in the cheer girls costume (probably before she was taken by Vecna in Eddie’s cabin house.https://www.instagram.com/reel/CeMhgfjg4me/?utm_source=ig_embed&ig_rid=eefddfb8-1662-46d3-89b5-5767aa7aae96 
Papa and Eleven, being happy in some parallel world, where things don’t go upside down.https://ew.com/thmb/xc88WOheq1xFD8jUQIJvHF78zLI=/1500×0/filters:no_upscale():max_bytes(150000):strip_icc()/13732356_1648725565453718_1776683220_n-73c1530256b64ceb96d8c1cc6f7e845e.jpg 
Not a BTS moment. Just some funny video being edited by some fan guy that I found cool.https://www.youtube.com/watch?v=yWCDYRthiIQ 

Stranger Things may scare the life out of us on-screen, but off-screen it’s pure comedy gold — and honestly, I’d watch a whole spin-off of just their bloopers. The show name may be Stranger Things. But these kids were never strangers to each other—even during their early days of shooting!!!