John Krasinski Reveals He Secretly Played 'A Quiet Place' 's Monsters: 'I Kept It Quiet!'

John Krasinski‘s role in A Quiet Place was much more substantial than viewers think.

The actor, 38, visited Jimmy Kimmel Live! on Tuesday where he revealed that he didn’t just direct, co-write, and star as the protagonist in last spring’s hit horror thriller — he also played one of the film’s noise-seeking creatures themselves.

“Nobody knows it because I’ve kept it quiet,” Krasinski told Kimmel, whose ABC late night show is on a week-long trip to Brooklyn, New York.

Of course, Kimmel was prepared — with a photo of Krasinski in a full-body motion capture suit on set. According to Krasinksi, the whole thing came about when technicians at Industrial Light and Magic asked the Office alum how he envisioned his movie’s monsters moving.

“I said, ‘Well, this is how I think he’s gonna crawl,’ ” Krasinski recalled. “And they said, ‘Well, why don’t you throw on the suit?’ And I was like, ‘Totally!’ ”

“Then they took that picture and I thought I was auditioning for Lion King,” he joked, adding, “The commitment level was very high.”

Surprisingly, that wasn’t the biggest challenge of filming A Quiet Place. Krasinski also had to direct his wife, Emily Blunt, in the movie – a move Kimmel pointed out was “a risky thing to do.”

Krasinski, of course, knew that. Though he wrote the movie with her in mind, he says he never actually asked Blunt to play the role.

“It’s true,” he said. “I got so scared. First, that she would say ‘no,’ because that’s just gonna be an awkward dinner. But I was actually more afraid that she’d say, ‘Yes, I’ll do it for you.’ ”

“I’ve been next to her when she’s made all these amazing decisions and she’s without a doubt the classiest, smartest, most dedicated actress I’ve ever known,” Krasinski added. “And when you see how much she puts into every role, I didn’t want her to come to set just for me.”

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Blunt, 35, went ahead and made the first move, asking her husband to read the script.

“[When she finished], she genuinely looked sick,” Krasinski teased. “I was reaching for a barf bag thinking she was gonna throw up, and instead she said, ‘You can’t let anyone do this movie.’ ”

“It was like a romantic comedy, where she was like proposing to me,” he continued. “She was like, ‘You have to let me play this part.’ And I think I just screamed, ‘Yes’ on this flight.”

Jimmy Kimmel Live! airs weeknights (11:35 p.m. ET) on ABC.