"Bigfoot's real," she told PEOPLE when asked about her shared connections to the Comic-Con faithful. "And I have confidence in myself that if I were ever to be taken out on an expedition … I would be the one to find Bigfoot."
The actress, 28, also says she's been "pretty vocal about how I'm a Lord of the Rings geek." And at a press conference for the reboot of Teenage Mutant Ninja Turtles, in which she plays April, she said she feels quite at home at the convention.
"I've walked the floor," she said. "I came once when my husband [Brian Austin Green] was here for Sarah Connor. I wasn't promoting anything. I came in a Star Wars T‑shirt, and I walked around and nobody bothered me one time."
Fox's sons are a little young to appreciate Teenage Mutant Ninja Turtles. Indeed, Bodhi, born this past February, was in her belly during the shoot. But costar Will Arnett's kids are 5 and 3 – and were thrilled at their dad's new gig.
"My kids watch the Nickelodeon show, which I think is really terrific and really funny, really good," he says. "And it just kind of coincided with the time the movie came out. Like, hey, they are putting out a Teenage Mutant Ninja Turtle movie. No way! My kids are going to lose their minds, which they did!"
He adds: "My kids were able to come in and enjoy it a lot. We shot in New York last summer, and it was just awesome having them there. They were just so excited."
With reporting by MELODY CHIU and SCOTT HUVER