When Rocky, Tiny, Mazu, and Bill find a lost egg, they're not sure what to do with it. Play ball? Probably not. The gang, with Rocky in the lead, sets out to find the egg's family. Turns out looking after such a delicate thing isn't easy, and asking all the residents of the Cretaceous jungle for advice is complicated. Some want to help care for the egg - but others want to eat it! When Gigantosaurus stomps onto the scene, everyone gets a big surprise - but it's not as surprising as what eventually hatches from the little lost egg!