South Park: Season 3, Episode 4

3 - 4: Jakovasaurs

While camping out at Stark's Pond, the boys discover a prehistoric creature. The Department of the Interior claims it is a "Jakovasaur", and wants to breed it to re-establish the species. Once they do, and the creatures are found to be incredibly annoying, everyone wants to get rid of them - except Cartman, who fights to preserve them.