The Indians called it the Thunderbird, a winged monster so vast that the beating of its mighty pinions sounded like thunder. But this ancient beast is not to be held in the cage of mythology. Today, from all over the dusty U.S. / Mexican border come hair-raising stories of modern day encounters with winged monsters of immense size and terrifying appearance. Further field sightings of similar creatures are recorded from all around the globe. The Kongamato of Africa, the Ropen of New Guinea and many others.