On the Korean Peninsula, the playful Tarbosaurus named Patch often disrupts forest residents like the Microraptor. While his mother hunts Protoceratops, Patch encounters Velociraptor eggs, leading to a protective attack by their mother, which Patch's mother swiftly counters. Amid various adventures and challenges, including rival dinosaur encounters and Velociraptor threats, Patch grows and learns to hunt. Despite some failures and the loss of his siblings to predators and harsh conditions, Patch eventually succeeds in hunting independently. Forced by his mother to start a new life alone, he departs, signaling his future dominance with a mighty roar.

Patch, now an adult, successfully hunts a Tsintaosaurus, causing the herd to mourn and scold him. Angered, he roars, driving them away. The smell of blood attracts a respectful pack of Velociraptors who wait for Patch to eat before they consume the remains. During mating season, Patch remains initially solitary but eventually finds and claims a mate, fending off a rival male. Together, they have two offspring. Tragedy strikes when both younglings are killed by predators. Patch avenges one by killing a Therizinosaurus but is severely wounded. Deserted by his mate, Patch succumbs to his injuries, ending his reign as forest king.