Factual error: The copper pot Jiminy looks into shows his reflection at a larger size. It should be reflected at a smaller size though.
Factual error: The famous battle between Stegosaurus and Tyrannosaurus Rex (which is incorrectly depicted as having three claws) never took place: Stegosaurus was extinct before Tyrannosaurus evolved. (Stegosaurus lived in the Jurassic, Tyrannosaurus in the Cretaceous.)