Lucian De Sacrificiis 14

[14] These practices are all very well, no doubt, and also those of the Assyrians and those of the Phrygians and Lydians; but if you go to Egypt, then, ah! then you will see much that is venerable and truly in keeping with Heaven—Zeus with the head of a ram, good Hermes with the head of a dog, Pan completely metamorphosed into a goat, some other god into an ibis, another into a crocodile, another into a monkey!

Wouldst thou enquire the cause of these doings in order to know it,

Iliad6, 150. you will hear plenty of men of letters and scribes and shaven prophets say—but first of all, as the saying goes, —that on the eve of the war, the revolt of the giants, the gods were panic-stricken and came to Egypt, thinking that surely there they could hide from their enemies; and then one of them in his terror entered into a goat, another into. a ram, and others into other beasts or birds; so of course the gods still keep the forms they took then. All this, naturally, is on record in the temples, having been committed to writing more than ten thousand years ago!

[14] But all this, and all that Assyria, Phrygia, and Lydia can show, amounts to nothing much. If you would see the Gods in their glory, fit denizens of Heaven, you must go to Egypt. There you will find that Zeus has sprouted ram’s horns, our old friend Hermes has the muzzle of a dog, and Pan is perfect goat; ibis, crocodile, ape,—each is a God in disguise. And wouldst thou know the truth that lurks herein? If so, you will find no lack of sages and scribes and shaven priests to inform you (after expulsion of the profanum vulgus) how, when the Giants and their other enemies rose against them, the Gods fled to Egypt to hide themselves, and there took the form of goat and ram, of bird and reptile, which forms they preserve to this day. Of all this they have documentary evidence, dating from thousands of years back, stored up in their temples.