The saltwater crocodile is among the largest living reptiles. Aldabra Giant Tortoise is one of the largest tortoises in the world and giant species of Tortoise native to the Aldabra Islands in the Indian ocean. Giant tortoises are the herbivorous animal and also the largest animal in its environment. Aldabra Giant Tortoise. The list of largest reptiles includes living crocodilians that reach a length of 6 m (20 ft) and more, such as Orinoco crocodile ( Crocodylus intermedius ), American crocodile ( C. acutus ), Nile crocodile ( C. niloticus ), saltwater crocodile ( C. porosus ), gharial ( Gavialis gangeticus) and false gharial ( Tomistoma schlegelii ).