Photo: Photographer: Alison Rosa/? Alison Rosa

Despite having more screen time than many of the human actors in Inside Llewyn Davis, the Coen brothers’ much-heralded film about the Greenwich Village folk scene in the sixties, the cat who becomes the title character’s accidental companion doesn’t receive an acknowledgement in the credits. Maybe that’s because the red Mackerel, which goes nameless for much of the movie, is actually portrayed by three tabbies, making onscreen crediting cumbersome. But the pesky feline — whose name the flailing folkie played by Oscar Isaac ultimately learns is Ulysses — figures prominently in the story. As Joel Coen explained at the Cannes Film Festival last May, “The film doesn’t really have a plot. That concerned us at one point; that’s why we threw the cat in.” Maybe the Cannes jury members were cat lovers; they awarded the film the festival’s 2013 Grand Prix prize.

The person responsible for helping the Coens get shots of their talented but hapless hero dealing with a tabby prone to barrelling down fire escapes, breaking free in subway cars, running down city streets, and becoming Llewyn’s mate on a road trip (during which Roland Turner, a surly jazz musician played by John Goodman, lobs putdowns), was veteran animal trainer Dawn Barkan. You know her work: Her credits include Ace Ventura: Pet Detective, Runaway Bride, and Snow Dogs, and she’s the trainer — please don’t call her a “wrangler” (that’s for sheep and cows) — responsible for Mr. Jinx being able to use the toilet in Meet the Parents.

It would seem like the stunts for this film would be simpler than potty-training. But in an interview with Vulture, Barkan says that elements of this job, her first time working with the Coens, were among her most challenging. “Much of what was scripted is a scary thing for a cat,” she says. “[But the Coens have] worked with animals in just about every film they’ve done, so they had an idea of what it takes.”

With six weeks to prep five rescue cats — two were fired prior to shooting for “temperament” issues — Barkan played to the strengths of the remaining trio. Tigger, a female, was the “holding” cat, the one Llewyn Davis carries around everywhere. Jerry was the “action” cat because he proved adept at “patterning” — a series of behaviors rewarded with a treat, like chicken. And Daryl was “the laid-back dude who could be put in hairier situations,” says Barkan. So that’s Jerry in the more sedate subway scenes, and Daryl whenever the subway stations and cars are overcrowded or too thunderous. At one point, Barkan says, even the usually chill Daryl got spooked by the noise and jostling, and clipped Isaac in the face. “For weeks, I said it wasn’t a good idea to shoot in a live subway station,” she says. “An actor getting scratched, I don’t ever want that to happen.”

Barkan hired Tigger, Jerry, and Daryl for Inside Llewyn Davis from outside sources, but Barkan cares for three of her own cats, including Peanut, 14, and Charlie, 8, the remaining Himalayans who portrayed Mr. Jinx. (Mischa, the original Meet the Parents toilet-flusher, and the other members of the Focker menagerie are long gone.) And when it came to choosing another animal for a hard-to-film moment in what’s perhaps the movie’s most devastating sequence, Barkan suggested her dog Finn, one of five rescues she takes care of personally. (She also owns a horse.) Barkan says that Ethan Coen loved the idea so much that he even filmed the behind-the-scenes action as a foxtail was attached to the Brussels Griffon.

In interviews, Isaac has said that he had to learn a new style of guitar playing for this role. But did he overcome the scratching incident to become a “cat person” during the shoot? “He was willing to do what had to be done and he was very kind about it,” says Barkan, explaining that actors’ and actresses’ pet predilections don’t matter for her to do her job effectively. “[Actors] can make life easier or more difficult, but they’re just a prop. The animals are working for the trainer.” Prop might not be the word we’d use to describe Isaac or his memorable performance, but if that attitude is what it took to help the Coens create an iconic movie cat, so be it.