Get an exclusive look at the raunchy, R-rated dog comedy, out Aug. 18.
"It's about time there was a dog movie that wasn't for kids!"
Through his adventures -- a far cry from family-friendly pet flicks like Homeward Bound -- Reggie meets Bug, a tough-talking Boston Terrier voiced by Jamie Foxx, Hunter, a therapy Great Dane voiced by Randall Park, and Maggie, an Australian Shepherd voiced by Fisher.
In ET's exclusive first look at the film, directed by Josh Greenbaum and produced by Phil Lord and Christopher Miller, fans see how Reggie's newfound friends convince him to exact revenge on his deadbeat owner, Doug (Will Forte).
"It's a talking dog movie," Ferrell says in the clip. "It's seemingly super sweet, but it's filthy, R-rated."
"I was just floored by the unbridled shenanigans," Park agrees.
Watch the full behind-the-scenes clip -- which includes footage of Foxx recording some of his character's bawdy dialogue prior to his recent health struggles -- in the video above.
The film also stars Sofía Vergara, Josh Gad, Harvey Guillén, Rob Riggle, Brett Gelman, Jamie Demetriou and Dennis Quaid.
Strays is in theaters Aug. 18.