When Reggie (Will Ferrell), a naïve, relentlessly optimistic Border Terrier, is abandoned on the mean city streets by his lowlife owner, Doug (Will Forte; The Last Man on Earth, Nebraska), Reggie is certain that his beloved owner would never leave him on purpose. But once Reggie falls in with a fast-talking, foul-mouthed Boston Terrier named Bug (Oscar® winner Jamie Foxx), a stray who loves his freedom and believes that owners are for suckers, Reggie finally realizes he was in a toxic relationship and begins to see Doug for the heartless sleazeball that he is and is determined to seek revenge.