Best of 2021 (Behind the Scenes): How Squid Game's killer robot became nightmare fuel

One of the biggest surprises of 2021 — already a year full of surprises (both great and terrible) — was Squid Game. In less than a month after its September release, Netflix's Korean survival drama went from completely unknown to must-see TV despite getting practically no official promotion. Viewers flocked via word-of-mouth to the bloody series about 456 down-on-their-luck people trying to win millions of dollars in a life-or-death competition of six playground games. Squid Game quickly became the streaming service's biggest series launch ever and the first Korean series to hit No. 1 in the U.S. It topped the charts in all 94 countries where Netflix has a top 10 list. It was, in short, an international phenomenon.

Squid Game accomplished a lot in bringing Korean representation into mainstream pop culture. It introduced well-known Korean stars like Lee Jung-jae to a global audience. And one of the biggest breakouts of the series was a giant killer robot overseeing a brutal five-minute round of Red Light, Green Light for the first game. The four-meter-tall doll detects anyone who moves — or even flinches — after stopping, and contestants are shot dead on the spot, alerting everyone in the game for the first time that losing has fatal consequences. It's the show's first of many jaw-dropping reveals, made all the more impactful by how terrifying the motion-sensing robot looks.

But it turns out the killer robot was almost even more traumatizing than how it actually appears onscreen. EW spoke with Squid Game creator/director Hwang Dong-hyuk about how the robot was brought to life — and how other aspects of the series have taken the world by storm.

When the giant killer robot makes her debut near the end of the first episode of Squid Game, her laser focus motion sensor technology is the reason why over half the players die almost immediately — and in the bloodiest, most violent ways imaginable. Her head rotates 360 degrees to catch anyone who moves and her eyes are cameras, making sure no one escapes her murderous sight. She's pure nightmare fuel. And the fact that she's designed to look like a childlike doll makes her even scarier.

"We were really wrestling with what kind of design to come up with but there was an agreement that we wanted to create a child character for the robot," Hwang tells EW. "Our production designer actually had the idea of using the character Younghee, which comes from an elementary school textbook that every single Korean learns from. I thought that was a really great idea."

And the first version of Younghee was actually even more horrifying — if you can believe it. "When I wrote it in the first draft of my script, I actually envisioned about 10 smaller robots about one meter tall," Hwang says. "I thought about putting them in line, about 10 of them. But through many conversations with the team, I felt that it'd be better to go with one huge robot that's more symbolic. I felt like that would be more powerful." Mission accomplished.

As for that catchy Red Light, Green Light melody that went viral on TikTok, that's another concept Hwang borrowed from a childhood memory. "This is not something that we had to come up with because this has been passed on through generations of children," he says. "That's exactly the melody that we use when we play that game that has been translated into Red Light, Green Light. Any Korean child knows of this melody. That directly translates to 'the mugunghwa flower has blossomed.' Mugunghwa is the national flower that represents Korea."

Along with the Red Light, Green Light doll and melody, Squid Game continued to subvert many other ideas from youth into something deadly throughout the entire season. "The basic concept that guided the overall decisions of creating the look and feel of the show is that we go back to our childhood," Hwang says. That's why all the players wear green tracksuits: "One thing that I had always known, ever since I wrote the first draft, was that I wanted all of the participants to be in tracksuits because in Korea, when we were kids in school for P.E. we all changed into these tracksuits."

Not long after Squid Game's Sept. 17 premiere, the green tracksuits and the doll were everywhere. Obsessed fans wore Squid Game costumes for Halloween, flocked to giant replicas of Younghee in cities around the world, played real-life versions of the games (without fatal consequences, of course), and danced to remixes of the Red Light, Green Light melody at massive music festivals. Watching fans bring Squid Game to life in the real world left Hwang "in awe."

"Throughout the production process, we would talk about it — how if the show did well, maybe there's going to be people who want to play Red Light, Green Light," Hwang says. "We had heard that with the success of Netflix's Korean series Kingdom there was this fad of 'gat,' which is the traditional Korean hats featured in the show. So we were thinking we might have to get ready to sell some dalgona (the honeycomb). We were half joking, but it was more coming from a place where we really hoped that people would love what we created rather than expecting what would happen."

Hwang believes this response means being a TV fan "has become something greater than just watching a series and enjoying it" and applies to more than just how much people love Squid Game.

"Seeing the costumes, watching people actually wanting to play the games physically, and the remix of our music being played and enjoyed by so many people at the EDM festivals, I feel like content is no longer something that you just watch and enjoy," he says. "It has evolved into something that you share with other people and enjoy together with everyone as part of pop culture. Even being the creator of this, I still am amazed. It's truly inexplicable."

But after the year (and a half) we've all had, it makes sense that a TV show would take over our lives in the real world too. Even if it involves a giant killer robot.

A version of this story appears in Entertainment Weekly's January issue, on newsstands Dec. 17 and available to order here. Don't forget to subscribe for more exclusive interviews and photos, only in EW.

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