

Snowball is convinced and takes them to his underground lair. Nevertheless, Snowball, the leader of The Flushed Pets, appears and saves Ripper, who is also caught by the Animal Control, and Max and Duke persuades Snowball to unlock their cage by claiming they are not domestic dogs. Their collars are stolen, which causes them to get captured by two Animal Control officers. At first, he tries to abandon Max there but they both are defeated by Ozone and numerous cats. He runs into a street where Ozone, the leader of a cat gang called The Alley Cats, are at. This drives Duke to deceive Max into downtown New York, while other dogs are distracted by a butterfly. On the other hand, Duke eats Max's dog food so Max begins to threaten Duke by breaking things in the apartment and later treats Duke as a servant when he, Buddy, Mel and several other dogs are taken to the dog park. The next morning, Chloe advises him that he needs to do more or else his life would be ruined. When they are about to sleep, Duke sleeps where Max is supposed to sleep and snores.

Duke accidentally breaks a ball Buddy found, which Katie thought it's their missing ball. Max becomes more upset about how Duke behaves. Although Katie introduces Duke to Max as his new brother, Max does not want to live with a new dog Duke licks Max even if Max snarls at him, which makes Max disgusted. One day, Katie adopted him from the pound. When Duke was a young puppy, he had a owner, named Fred, but he ran off chasing a butterfly and he could not find his way back, which has resulted in the Animal Control putting him in custody. Young Duke playing with his old owner Fred.
