Dug, along with his sidekick Hognob, unite a cavemen tribe to save their hidden valley from being spoiled and, all together as a team, to face the menace of a mysterious and mighty enemy, on the turf of an ancient and sacred sport.
Some dinosaurs are hit by a meteorite at the beginning, but are shown at the end to be fine. A rabbit is caught and tied to a spit over a fire, but escapes unharmed. Hognob and all mammoths are fine. Some caterpillars are made into shoes.