Angelina Jolie
Credit: Vera Anderson/WireImage

If you’ve read Unbroken, the 2010 Laura Hillenbrand book that Angelina Jolie’s Unbroken is adapted from, you will no doubt remember one particularly horrific passage involving a little duck named Gaga. Louie Zamperini (portrayed by Jack O’Connell in the film) had already suffered an extraordinary amount when he became a prisoner-of-war during WWII—including surviving a plane crash and spending 47 days adrift in a raft in the Pacific. Gaga was a friendly duck that used to hang around the camp and lift the soldiers’ spirits.

Zamperini told Hillenbrand that the event that haunted him the most was when a sadistic Japanese guard tortured and killed Gaga in a truly terrible way; read the book if you must know more. (This episode traumatized so many readers that Hillenbrand didn’t include it for a new edition aimed for a YA audience. “I know that if I were 12 and reading it, that would upset me,” Hillenbrand told The New York Times. )

Angelina Jolie felt similarly. “We were never going to do what really happened to Gaga because we felt like it was unnecessary,” she says.

But Jolie did want to have a duck in the film as a representation of Gaga. Easier said that done: “So it was like: ‘Okay, we need to find a really skinny duck with a limp,'” she says. “So we had a search. We found some ducks but they were big and too healthy,” she says with a laugh. “So they put the ducks on a diet and then the one who would be Gaga had to have a splint on. We were actually having meetings about the ducks! So we tried these splints, but it was bothering [the duck’s] legs. It just made the duck want to lay down.” She laughs again. “At a certain point we just thought, yeah, okay, we can’t do this.”