How Strays cast its raunchy, four-legged stars

Strays has a star-studded voice cast that includes Will Ferrell, Jamie Foxx, Isla Fisher, and Randall Park, but some of the movie's biggest breakouts are total unknowns. Four-legged unknowns.

Josh Greenbaum's canine comedy centers on four dogs, who embark on an R-rated adventure to seek revenge against an abusive owner (Will Forte). The motley crew of mutts include the scruffy border terrier Reggie (Ferrell), Boston terrier Bug (Foxx), Australian shepherd Maggie (Fisher), and Great Dane Hunter (Park).

Producers Phil Lord and Chris Miller tell EW that when it came time to cast the four canine actors, seemingly every member of the production had their own opinions. "There was a lot of discussion about what breeds the dogs were and which breeds would play well off of each other," Miller explains. "Everybody had their own [input] and was like, 'Well, my dog is this.'"

"Obviously, the labradoodle is the cutest," Lord interjects.

"Not true!" Miller says with a laugh. "I have a cavapoo, and she's the cutest."

Elsa, the Australian shepherd who plays Maggie, had previous acting experience, but the other three lead dogs were total newbies. Some proved to be professionals, like Sophie, the border terrier who plays star Reggie. Meanwhile, Dalin, the enormous Great Dane who plays Hunter, was still a puppy during filming, so he would get bursts of energy and zoom around the set, knocking over equipment. (I.e. Zoomies!)

Universal Studios Reggie (Will Ferrell), Maggie (Isla Fisher), Hunter (Randall Park), and Bug (Jamie Foxx) in 'Strays'

And of course, filming with a pack of dogs — without human dialogue — made for an unusual shooting environment. "It's a very surreal and quiet set because there's not a lot of improv," Miller explains. "It's just like: 'Let's get these cute little muffins to get to the spots where they're supposed to be.'"

The film's raunchy rating also meant that the trainers had to teach the dogs to perform decidedly R-rated tricks. (EW has an exclusive clip from the film above, where the four dogs hump lawn ornaments.) Director Greenbaum (Barb and Star Go to Vista Del Mar) explains that the trainers taught the dogs to hump objects on command, using the command words, "Humpity humpity."

"It's a movie that's very smart about being silly," Lord adds. "It's written by Dan Perrault, who we've always admired from the show American Vandal. The movie really goes there, and it takes a big swing, but it's also very big-hearted and warm. You get the sense that the movie's friendly, even though it's very naughty."

Universal Studios Reggie (voiced by Will Ferrell) in 'Strays'

To play Reggie's abusive owner Doug, Lord and Miller also turned to a frequent human collaborator: Forte, television's Last Man on Earth. After all, the producers note with a laugh, not every actor would willingly volunteer to star as a grumpy villain who's mean to dogs.

"That's a part that's really hard to cast because the character has to be somebody who's such a jerk that you're rooting for him to get a big, disgusting comeuppance," Miller says. "But he can't be so awful that you don't like watching him. The joy about Will Forte is that he's such a sweet, kind person, and you can tell that even when he's playing a jerk, he's not really a jerk."

Strays is in theaters this Friday.

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