Dragons are advanced varanoid reptiles which closest relatives are monitor lizards. Since the late Cretaceous they conquered a lot of habitats and are today still a worldwide existing group. But they are critical endangered. And before they could vanish forever scientists try to learn as much as they can about these animals to understand and better protect them. This folder also explores a little the biology and natural history of the Natrixosaurs, or sea serpents, a clade distantly related to dragons, and often called (wrongly) sea dragons.