Molesaurus was the first of many monsters sent by Rodak to destroy Earth. It had an H-Bomb inside it so if Molesaurus failed, Rodak could still cause widespread destruction. Whilst on Earth, Molesaurus makes itself a nest and then destroys a train. When a helicopter comes to investigate, Molesaurus leaps out of the ground and destroys that also. Later, Goldar arrives and the two fight, but Goldar proves to be far too powerful and it flee's to the centre of the Earth. Later, Goldar picks up Molesaurus and leaves him in the North Pole were Rodak set him to explode, not knowing his monster had been placed elsewhere.