"Chrysaor was joined in love to Callirrhoe, the daughter of glorious Ocean, and begot three-headed Geryones. […] And in a hollow cave she bare another monster, irresistible, in no wise like either to mortal men or to the undying gods, even the goddess fierce Echidna who is half a nymph with glancing eyes and fair cheeks, and half again a huge snake, great and awful, with speckled skin, eating raw flesh beneath the secret parts of the holy earth. And there she has a cave deep down under a hollow rock far from the deathless gods and mortal men. There, then, did the gods appoint her a glorious house to dwell in: and she keeps guard in Arima beneath the earth, grim Echidna, a nymph who dies not nor grows old all her days. Men say that Typhaon the terrible, outrageous and lawless, was joined in love to her, the maid with glancing eyes. So she conceived and brought forth fierce offspring; first she bare Orthus the hound of Geryones, and then again she bare a second, a monster not to be overcome and that may not be described, Cerberus who eats raw flesh, the brazen-voiced hound of Hades, fifty-headed, relentless and strong. And again she bore a third, the evil-minded Hydra of Lerna, whom the goddess, white-armed Hera nourished, being angry beyond measure with the mighty Heracles. […] She was the mother of Chimaera who breathed raging fire, a creature fearful, great, swift-footed and strong, who had three heads, one of a grim-eyed lion; in her hinderpart, a dragon; and in her middle, a goat, breathing forth a fearful blast of blazing fire. […] Echidna was subject in love to Orthus and brought forth the deadly Sphinx which destroyed the Cadmeans, and the Nemean lion, which Hera, the good wife of Zeus, brought up and made to haunt the hills of Nemea, a plague to men."
– Hesiod's Theogony
"Come, now, tell me, where hast thou proved thyself a seer? Why, when the Watcher was here who wove dark song, didst thou say nothing that could free this folk? Yet the riddle, at least, was not for the first comer to read; there was need of a seer's skill; and none such thou was found to have, either by help of birds, or as known from any god: no, I came, I, Oedipus the ignorant, and made her mute, when I had seized the answer by my wit, untaught of birds."
– Sophocles, Oedipus the King
"Then someone suggested that their plaything should be exhibited in the nearest building, and so I was led past the sphinx of white marble, which had seemed to watch me all the while with a smile at my astonishment, towards a vast grey edifice of fretted stone."
"Above me towered the sphinx, upon the bronze pedestal, white, shining, leprous, in the light of the rising moon. It seemed to smile in mockery of my dismay."
"I stopped very gently and sat upon the Time Machine, looking round. The sky was no longer blue. North-eastward it was inky black, and out of the blackness shone brightly and steadily the pale white stars. Overhead it was a deep Indian red and starless, and south-eastward it grew brighter to a glowing scarlet where, cut by the horizon, lay the huge hull of the sun, red and motionless. The rocks about me were of a harsh reddish colour, and all the trace of life that I could see at first was the intensely green vegetation that covered every projecting point on their south-eastern face. It was the same rich green that one sees on forest moss or on the lichen in caves: plants which like these grow in a perpetual twilight."
— H. G. Wells, The Time Machine
"To the North-West I looked, and in the wide field of my glass, saw plain the bright glare of the fire from the Red Pit, shine upwards against the underside of the vast chin of the North-West Watcher—The Watching Thing of the North-West… 'That which hath Watched from the Beginning, and until the opening of the Gateway of Eternity' came into my thoughts, as I looked through the glass…"
"[O]lden sciences […], disturbing the unmeasurable Outward Powers, […] allowed to pass the Barrier of Life some of those Monsters and Ab-human creatures, which are so wondrously cushioned from us at this normal present. And thus there had materialized, and in other cases developed, grotesque and horrible Creatures, which now beset the humans of this world. And where there was no power to take on material form, there had been allowed to certain dreadful Forces to have power to affect the life of the human spirit. And this growing very dreadful, and the world full of lawlessness and degeneracy, there had banded together the sound millions, and built the Last Redoubt; there in the twilight of the world."
"And then, so it would seem, as that Eternal Night lengthened itself upon the world, the power of terror grew and strengthened. And fresh and greater monsters developed and bred out of all space and Outward Dimensions, attracted, even as it might be Infernal sharks, by that lonely and mighty hill of humanity, facing its end—so near to the Eternal, and yet so far deferred in the minds and to the senses of those humans. And thus hath it been ever."
— William Hope Hodgson, The Night Land
"At length they came to the door upon the outer court, and they halted. Even from where they stood they felt the malice of the Watchers beating on them, black silent shapes on either side of the gate through which the glare of Mordor dimly showed. […]
"Sam drew out the elven-glass of Galadriel again. As if to do honour to his hardihood, and to grace with splendour his faithful brown hobbit-hand that had done such deeds, the phial blazed forth suddenly, so that all the shadowy court was lit with a dazzling radiance like lightning; but it remained steady and did not pass.
"'Gilthoniel, A Elbereth!' Sam cried. For, why he did not know, his thought sprang back suddenly to the Elves in the Shire, and the song that drove away the Black Rider in the trees.
"'Aiya elenion ancalima!' cried Frodo once again behind him.
"The will of the Watchers was broken with a suddenness like the snapping of a cord, and Frodo and Sam stumbled forward. Then they ran. Through the gate and past the great seated figures with their glittering eyes."
— J. R. R. Tolkien, The Lord of the Rings