Matt Duffer: Every moment, every beat is mapped out. We're talking about a month-long process just for that 15 seconds.

[shrieking, roaring]

[GFX: Behind the FX]

Matt Duffer: Hey, I'm Matt Duffer.

Ross Duffer: I'm Ross Duffer. We're the creators of Stranger Things, and we're gonna talk through what we call the Demo fight.

[GFX: Updating the Demogorgon]

[grunts, roaring] 

Matt Duffer: So the Demogorgon, we conceived of him, what, seven years ago. It was a collaboration with an artist, Aaron Sims. We looked at a million different designs for what this monster could look like. We talked about all the monsters who had scared us over the years, and we just explored. We knew he'd come from this other dimension. We knew he was gonna be humanoid. But that's roughly when we started designing him, that's when we knew. And why we wanted him to have a kind of human look, really, it's because in season one, in particular, we wanted to be able to shoot a man in a suit. We wanted to be able to do it practically. 

Ross Duffer: We were very limited in season one in terms of how much we could show him. Had to keep him in shadow. There were a few computer graphics shots, like when he bursts out of the wall. 

Matt Duffer: We did try them practically. 

Ross Duffer: We attempted practically, and it's a good thing no one saw. It'd be Mystery Science Theater kind of quality. But what we really wanted to do with this season is, okay, he's always been in shadow. We haven't really been able to show what this creature can do, really, in terms of movement, in terms of how he attacks. We wanted to go, "Okay, let's let this thing loose and see what it can do."

[screams, grunts] 

[GFX: Animating the Demogorgon]

Ross Duffer: There's no mocap involved. This is just pure animation. Rodeo, the company that did this, is really creating a character here through the animation.

Matt Duffer: The first animation pass, that's when you're seeing what looks almost like just a gray clay rendering. When it's in that stage, we and our visual effects supervisors are able to give notes. I want him to roar longer. I want him to swipe at the end of this because that'll help with the cut to the next scene. You give those kind of animation notes, they're able to do it a lot easier when it's in this rough stage. And then, once you've locked on that, then you move into the rendering stage. That's when things start to get really exciting. So it's the same animation, but they get the skin, they get the snow, the lighting.

Ross Duffer: That's where he really comes alive that it's like, "Oh, wait." "There's the Demogorgon. There he is." And it's really exciting when those shots finally come together and all the elements just meld and you get what you guys see as the final look.

[shrieks]

[GFX: Practical and Digital Merged]

[yells, grunts] 

Matt Duffer: When the Demogorgon first bursts out, we wanted it to be a moment where the audience just goes, "Holy moly." So in order to do that, we were like, "Let's not do a lot of edits." "Can we do this basically as a oner?"

Ross Duffer: I think it just feels more like he's in the space as opposed to, "Oh, here's our actor. Here's a visual effects shot." It just ties it all together.

Matt Duffer: Because of the amount of stunts involved, because we didn't want to be using CG people on top of a CG monster, we wanted to use real stuntmen, so we weren't able to do it all in one shot, so it's about three big stunt sequences that are stitched together.

Ross Duffer: It really was to protect our stunt team and make sure that we weren't doing those stunts often. So each stunt is essentially its own little moment. You only have a few chances to get it right, so it was important that everyone was pre-dialed in when we got there. Our stunt coordinator, Hiro Koda, there were a few days of rehearsal where he was just working with his team. Then we brought our camera operator in, and he also worked with our stunt coordinator. Be like, "I like this, but maybe what if we swing over here at this moment?"

Matt Duffer: When the Demogorgon throws that guy and the bar collapses, that's actually a mistake. That bar was not supposed to come down like that, but we just thought it was cool. The camera wasn't perfect, but we're like, "If we try that again, we'll never be able to recreate it." And we decided, "You know what? Let's stick with it." I kind of like the messiness and rawness of the camera. It just makes it feel that much more real. 

Ross Duffer: It really was a coordination of a lot of different compartments just to get here.

[Hopper yelling]

[GFX: Hopper Vs. The Demogorgon]

[growling] 

Matt Duffer: When we're working on a Demogorgon sequence, the way that we do it is we just edit the sequence with nothing. We would shoot it, or at least rehearse it, with this-- a man in a green suit. Sometimes he would have a tennis ball at the top of his head to show us how tall the Demogorgon was. It's important for both David, us, and the camera operators to know what height the actual monster was gonna be. But eventually, you also have to get it clean. 

Ross Duffer: In the edit, sometimes the takes with the man in the green suit were the best takes, so we went with those. And sometimes it was clean pass, which is why when you're looking behind the scenes, you're gonna see a little bit of both. What we try to do here, and this is practical with the fire, is just make sure every time we go to Hopper, there's a little less fire, there's a little less fire, the Demo's getting a little bit closer, a little bit closer. Just building the tension.

[grunts]

Matt Duffer: I think, originally, he was just supposed to jab the Demo in the mouth. But then, David…

Ross Duffer: "What if I throw it like a javelin?" 

Matt Duffer: Yeah, “Let me throw this sucker like a javelin.” I'm really happy David pitched that idea.

Ross Duffer: It's pretty epic.

[shrieking] 

Ross Duffer: With visual effects shots, the more that you can do practically that is real in your frame, the more it's gonna feel organic and you're gonna trick the audience's eye.

Matt Duffer: Let's take advantage of the amazing technology that's now available to us today, but also learn from the past and plan, plan, plan. 

Ross Duffer: So anyways, that's a little behind the scenes look of how we made this Demo fight come to life. Thanks for watching.

Matt Duffer: Yeah, thanks.