Thunderbird is a cryptozoological term used to describe large, bird-like creatures and are generally identified with the Thunderbird of Native American tradition. There were similar cryptids reported in the Old World called Rocs. These giant birds are regarded by a small group of researches as having lizard features like the extinct pterosaurs. The reports throughout the centuries and even fossil records show that giant birds with wingspans of between four and five feet long were coexisting with early man. Today, however, the creatures are regarded as myths and urban legends, even though people used Native American legends as evidence to back up their claims. One of the most famous stories of a Thunderbird was back in 1890 when two cowboys killed a creature that was a giant bird-like animal with a large wingspan that had smooth skin and a face that resembled an alligator. It was brought back to town and put up against a barn. It was reported in the local newspaper, but even though it was actually printed there is no further evidence that this event actually occurred. No one has been able to find any other supporting facts. Another reason that people call these giant birds Thunderbirds is because it was believed that when they flapped their wings it made a sound as loud as thunder. Birds can grow to be quite big so it would not be surprising if these monsters of birds actually did exist.