Quetzalcoatlus was perhaps one of the last and largest Pterosaurs ever to have lived, with an 10-11 metre wingspan, yet a hollow-boned lightweight body of less than 120 kilograms. It existed in the Late Cretaceous(80-65) of North America. It was named after the Meso-American Mayan and Incan feathered serpent god Quetzalcoatl. Once the largest known Pterosaur, Hatzegopteryx has now apparently taken this title.
Quetzalcoatlus featured in only a minor role in Episode 6: Death of a Dynasty, whereit made a very breif apperence and was nearly eaten by a Deinosuchus. It was the only pterosaur in the episode; which is further explained to be due to Quetzalcoatlus being the last of the Pterosaurs to evolve - wandering lonely giants. In the book however, several Deinosuchus fed on the Quezalcoatlus as one of them dragged it to its death.
Quetzalcoatlus might have been one of the pterosaurs flying around with the Pteranodons in The Most Dangerous Sea of Sea Monsters: A Walking with Dinosaurs Trilogy, but this is not certain and the creature never appeared in anything else. It also appeared in March of the Dinosaurs.