While trekking through the Jungle of Misery in Dino World, the gang see a monstrous beast. Buck tells it to "shoo", and it does, turning out to be a moth. Buck said that he had known it when it was a caterpillar, "you know. Before he... came out." These giant moths appear to be inhabitants of the Jungle of Misery.
They may be based on Carboniferous insects, which, due to the higher oxygen levels then, grew much bigger than modern insects. For example, the prehistoric dragonfly had a one-metre wingspan and was about as long. No insects as large as the Giant Moth have been found yet, however.