They have appeared throughout the centuries, long before aircraft were even conceived of, starting as native American legends from both South America and Central America. Some say they are birds, while others have suggested that they are bird-like gods. Whether they come from alien worlds or have evolved on this planet, they keep appearing from time to time, even into modern days. Some, which appear as the Rocs of old, are said to have entered our time and space from prehistoric dimensions.
The art from the ancient world is mostly Egyptian and Middle Eastern, and refers to mythological creatures which are often shown to be half men and half birds, usually with the head of a bird. But there are also gods that are shown with men's heads and giant wings. The North and South American worlds show them predominantly as birds, their thunderous passage coming from the sound of their wings. Those with alien associations suggest that the aircraft thunder as they roar through the skies.
They come in a vast range of colors and materials, from carved to sculpted to cast in precious metals. They are mostly thought of as imaginary, leaving their traces mostly in fantasy books, with legends of dragons and ancient gods. But if we were to turn off our television sets and spend more time beneath the night skies, scanning and wondering as the ancients did, we might see similar objects ourselves.
We can mistake meteors, weather balloons and light aircraft as giant birds. Even motionless planets can fool the casual observer. But despite common inhabitants of the sky, ancient observers have left us with numerious reports of abnormal sightings. Some witnesses have seen them in daylight at close range, and have left us with baffling descriptions.