In the movie Bringing Up Baby (1938), a scene where Susan’s dress is ripped was inspired by something that happened to Cary Grant. One night, while at the Roxy Theater, his pants zipper got caught on the back of a woman’s dress. Grant impulsively followed her, and when he later told director Howard Hawks the story, Hawks loved it and decided to include it in the film.
Katharine Hepburn and Cary Grant often spent time together outside of filming, going on double dates with their partners at the time, Howard Hughes and Phyllis Brooks. They enjoyed working on the film so much that they often showed up early, and since Hawks was usually late, they used the time to brainstorm new comedic ideas.
Hepburn was fearless around Nissa, the young leopard who played Baby in the film, even petting it. Grant, however, wasn’t as comfortable with the big cat, so a stunt double was used for scenes where his character interacted with the leopard. Hepburn once played a prank on Grant by putting a stuffed leopard through the vent in his dressing room. Grant, who was terrified, quickly fled the room. Hepburn later wrote in her autobiography, Me: Stories of My Life, that he was out of there “like lightning.”
Although Grant never actually said “Judy, Judy, Judy” in any film (a line often mistakenly attributed to him), he did say “Susan, Susan, Susan” in Bringing Up Baby.
Before the movie’s release, Grant was concerned that he might never become a major star, as he was already nearly 34, while younger actors like Errol Flynn and James Stewart were well-established stars. However, things worked out for him in the end.
Source: Cinema Shorthand Society