Brad Pitt deferred to a very special costar on his new film.

In a behind-the-scenes featurette for Heart of the Beast(in theaters Sept. 25) shared exclusively with PEOPLE, Pitt, 62, calls his German Shepherd colleague “number one on the call sheet” and “the star of the film.”

The David Ayer-directed thriller sees the Oscar winner as James, a retired Special Forces officer whose plane crashes in remote Alaska. His canine companion is Odin (played by a pooch named Uber), who rescues James after their crash and embarks on a journey of survival in the wilderness.

“In our story it’s James and Odin in the Alaskan outback, which turns into a survival story,” explains Pitt in the featurette, sitting alongside “good boy” Uber. “It’s really beautiful in the film how they work together and depend on each other,” the actor-producer says.

“What, now you’re camera shy?” Pitt jokes when the dog turns his gaze elsewhere. Following Uber’s lead and “improv-ing,” he adds, “is really how we do scenes.”

Odin, as played by Uber, is “the most important piece to this story,” concludes Pitt. “And it’s been a surprisingly special experience.”

In photos shared exclusively with PEOPLE, the Ocean’s Eleven alum and his pal Uber can be seen roughing it in New Zealand, where Heart of the Beast was filmed. An official synopsis calls the film “an intense adventure thriller that explores the unbreakable bond between a man and his best friend as they face their greatest battle yet.”

Richard Raymond, part of the production team alongside Pitt, took to X on June 11 to share the movie’s trailer and reassure fans that the canine hero makes it to the end of the story. “Everybody loves a dog,” he wrote. “It’s about the only thing the whole world agrees on. So let me put your mind at ease right now: the dog does not die. You’re welcome.”

Also among Pitt’s upcoming screen projects are reprising the role of Cliff Booth in a David Fincher-directed sequel to Once Upon a Time in Hollywood… plus the Edward Berger-directed The Riders and Ocean’s 14.