From ancient times stories about flying snakes in southern Arabia have abounded. Most of these stories were connected with frankincense trees. In ancient days it was believed that flying snakes inhabited the groves of frankincense trees, protecting them from intruders but also making it much more difficult for the owners of the trees to harvest the precious resin.
Recorded stories have come down to us from Greek historians like Herodotus (430 BC), Strabo, and others. However Pliny the Elder considered such stories to be fantasy.
However, it is interesting to note that even today there are people in the area who believe in flying snakes.
Oral traditions like these that have survived to today are largely independent of written sources, thus strengthening the argument that perhaps there is, or once was, a basis for the existence of such creatures.