The Histories,c. 425 BC
The crocodile has eyes like a pig’s but great fanglike teeth in proportion to its body, and is the only animal to have no tongue and a stationary lower jaw, for when it eats it brings the upper jaw down upon the under. It has powerful claws and a scaly hide, which on its back is impenetrable. It cannot see underwater, though on land its sight is remarkably quick. One result of its spending so much time in the water is that the inside of its mouth gets covered in leeches. Other animals avoid the crocodile, as do all birds with one exception—the sandpiper, or Egyptian plover; this bird is of service to the crocodile and lives, in consequence, in the greatest amity with him, for when the crocodile comes ashore and lies with his mouth wide open (which he generally does facing toward the west), the bird hops in and swallows the leeches. The crocodile enjoys this and never, in consequence, hurts the bird.