The film is a live-action and CGI R-rated comedy about an abandoned puppy named Reggie and other stray dogs who team up to take revenge on their former owner. It is said that dogs are man's best friend, but what if a dog owner is a big jerk? If so, it's time to assemble the Avengers. Reggie (voiced by Will Ferrell) is an innocent, optimistic and lively border terrier. Although he was abandoned by his scumbag owner Doug (played by Will Forte) on the cruel streets of the big city, Reggie still believes that his beloved owner would never abandon him intentionally. But when Reggie meets Bugs (voiced by Jamie Foxx), a Boston terrier who always loves to swear and speaks as fast as a machine gun, a freedom-loving stray dog who believes that only stupid dogs need owners, Reggie finally discovers that his dog owner Doug has been abusing him all along, and Doug is a heartless scumbag. To take revenge on this ruthless dog owner, Reggie, Bugs, and Bugs' best friend Maggie (voiced by Isla Fisher), a clever Australian shepherd whose owner has neglected her because she adopted another puppy, and Hunter (voiced by Randall Park), a Great Dane with anxiety who is always stressed out as an emotional support dog. They form the Revenge Dog Alliance, brainstorm, come up with a perfect revenge plan, and embark on an epic adventure to help Reggie find his way home, and finally make Doug pay the price by forcing him to bite off his favorite part of his body (friendly hint: it's not his feet).