You mean reptile with legs. That belongs to the Sauropoda Infraorder. It was a type of gigantic, long-necked, herbivorous, quadrupedal dinosaur that lived between the Late Triassic and the Late Cretaceous.
SAUROPODo infraorder of the sauropodomorph dinosaurs, which inhabited the entire planet, including Antarctica, in the Triassic period to the late Cretaceous.