St. John of Damascus on Dragons

For we trust the teaching of Moses, and, more exactly, the Holy Spirit, having spoken through [the prophet]. This [teaching] reads: And God brought them unto Adam to see what he would call them; and whatsoever [Adam] called every living creature, that was the name thereof (cf. Gen. 2:19). Hence, a dragon was one of the animals. I am not telling you, after all, that there are no dragons; dragons exist but they are serpents borne of other serpents. Being just born and young, they are small; but when they grow up and get mature, they become big and fat so that exceed the other serpents in length and size. It is said they grow up more than thirty cubits; as for their thickness, they get as thick as a big log. Dio the Roman (A.D. 155 – 236) who wrote the history of Roman empire and republic, reports the following: one day, when Regulus, a Roman consul, was fighting against Carthage, a dragon suddenly crept up and settled behind the wall of the Roman army. The Romans killed it by order of Regulus, excoriated it and sent the hide to the Roman senate. When the dragon’s hide, as Dio says, was measured up by order of the senate, it happened to be, amazing, one hundred and twenty feet long, and the thickness was fitting to the length.”

“There is one more kind of dragon; those have wide head, goldish eyes and horny protuberances on the back of the head. They also have a beard [protruding] out of the throat; this kind of dragons is called “agaphodemons” and it is said they have no faces. This dragon is a sort of beasts, like the rest of the animals, for it has a beard, like a goat, and horn at the back of its head. Its eyes are big and goldish. These dragons can be both big and small. All serpent kinds are poisonous, except dragons, for they do not emit poison.”

– St. John of Damascus, On Dragons (unavailable in English, but excerpted in an English article here)