Darlene, a plump tabby cat, is ostracized by Venus and the other animals for her weight. Believing her owner plans to send her away, she embarks on a desperate, extreme weight-loss journey. After enduring endless schemes and humiliation, she is abandoned at an animal shelter.
When she learns the truth — her owner never intended to get rid of her — she saves Venus with her thick fat reserves amid a frigid cold wave. She also resolves the long-standing hatred between Scar and Graypaw. In the end, she embraces her full figure, guards the farm and cares for all stray animals.