cheers!

There's a lot more mystery left to those isn't there?

The Sibyl of Erythraea, it is said, foretold that the city of Rome would finally be destroyed by the Perytons. In the year A.D. 642 the record of the Sibyl's prophecies was consumed in the great conflagration of Alexandria; the grammarians who undertook the task of restoring certain charred fragments of the nine volumes apparently never came upon the special prophecy concerning the fate of Rome. In time it was deemed necessary to find a source that would throw greater light upon this dimly remembered tradition. After many vicissitudes it was learned that in the sixteenth century a rabbi from Fez (in all likelihood Jakob Ben Chaim) had left behind a historical treatise in which he quoted the now lost work of a Greek scholiast, which included certain historical facts about the Perytons obviously taken from the oracles before the Library of Alexandria was burned by Omar. The name of the learned Greek has not come down to us, but his fragments run:

"The Perytons had their original dwelling in Atlantis and are half deer, half bird. They have the deer's head and legs. As for its body, it is perfectly avian, with corresponding wings and plumage. . . . Its strangest trait is that, when the sun strikes it, instead of casting a shadow of its own body, it casts the shadow of a man. From this, some conclude that the Perytons are the spirits of wayfarers who have died far from their homes and from the care of their gods. . . . . and have been surprised eating dry earth . . . flying in flocks and have been seen at a dizzying height above the Columns of Hercules. . . . they [Perytons] are mortal foes of the human race; when they succeed in killing a man, their shadow is that of their own body and they win back the favor of their gods. . . . and those who crossed the seas with Scipio to conquer Carthage came close to failure, for during the passage a formation of Perytons swooped down on the ships, killing and mangling many. . . . Although our weapons have no effect against it, the animal-if such it be-can kill no more than a single man. . . . wallowing in the gore of its victims and then fleeing upward on its powerful wings. . . . in Ravenna, where they were last seen, telling of their plumage which they described as light blue in color, which greatly suprised me for all that is known of their dark green feathers. Though these excerpts are sufficiently explicit, it is to be lamented that down to our own time no further intelligence about the Perytons has reached us. The rabbi's treatise, which preserved this description for us, had been on deposit until before the last World War in the library of the University of Dresden. It is painful to say that this document has also disappeared, and whether as a consequence of bombardment or of the earlier book burning of the Nazis, it is not known. Let us hope that one day another copy of the work may be discovered and again come to adorn the shelves of some library."

J.L. Borges "The Book of Imaginary Beings"