For the actress, the scariest moment on the film "was watching Matt Damon cry like a baby and rock back and forth when the snakes were spread all over the set."
Johansson grew up with reptiles, cats and horses, and had a degree of comfort around the working animals, but Damon wore his fear on his sleeve – and his face.
"He was pretty terrified," Johansson told PEOPLE at the movie's New York premiere Monday night.
"He was definitely sweating a bit, and maybe the sweat formed in the corner of his eye. I said, 'Matt, these kids are practically juggling the snakes. Hold it together.'"
"I'm afraid of snakes," Damon admitted. "And I got bullied into interacting with them by Scarlett and the kids."
There were other frightening moments for Damon, most memorably a scene where he had to sit inside a small car as a large bear pawed at the window.
"The size of the thing was so awesome and humbling," Damon said. "Something like that could just kill you by accident. They're just so huge and strong."