Many of the monsters of Greek mythology appear in Hesiod’s Theogony. More specific than that, many are children of one particularly scary pair:
(ll. 306-332) Men say that Typhaon the terrible, outrageous and lawless, was joined in love to her [Echidna], 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. And her Heracles, the son of Zeus, of the house of Amphitryon, together with warlike Iolaus, destroyed with the unpitying sword through the plans of Athene the spoil-driver. 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. Her did Pegasus and noble Bellerophon slay; but 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. There he preyed upon the tribes of her own people and had power over Tretus of Nemea and Apesas: yet the strength of stout Heracles overcame him.
The hound of Hades is sometimes shown with two heads and various body parts (a chimera) but the most familiar form is the three-headed Cerberus.
While Cerberus, one of Echidna’s children, is said to be fierce enough that the gods fear him, and flesh-eating, he is a watchdog in the land of the already dead. He lets people pass him in one direction, but eats them when they try to go back. In this way, he keeps the shades of the dead in place.
One of the Labors of Hercules was to fetch Cerberus. Unlike the countryside-devastating monsters that Herakles destroyed, Cerberus was harming no one, so Herakles had no reason to kill him. In order to bring Cerberus to King Eurystheus, Herakles had to overpower the beast, which he did. Cerberus was afterward returned to his place.
Euphorion, Fragments (trans. Page, Vol. Select Papyri III, No. 121 (1)) (Greek epic C3rd B.C.) :
“Behind, under his [Kerberos, Cerberus] shaggy belly cowering, the serpents that were his tail darted their tongues about his ribs. Within his eyes, a beam flashed darkly. Truly in the Forges or in Meligounis leap such sparks into the air, when iron is beaten with hammers, and the anvil roars beneath might blows,–or up inside smoke Aitna, lair of Asteropos. Still, he came alive to Tiryns out of Haides, the last of twelve labours, for the pleasure of malignant Eurystheus; and at the crossways of Mideia, rich in barley, trembling women with their children looked upon him.”
Chimera is now a term used to describe a creature composed of body parts from different animals. This label comes from the original Chimera, a composite of goat, lion, and serpent. She is sometimes called three-headed, and at other times three-bodied. Brought up to be a menace, by the Carian king Amisodarus, and associated with volcanoes, she breathed fire and devastated the countryside.
Aelian, On Animals 9. 23 (trans. Scholfield) (Greek natural history C2nd A.D.) :
“Homer may sing of the Khimaira (Chimera) with its three heads, the monster of Lykia kept by Amisodaros the Lykian king for the destruction of many, of varies nature, and absolutely invincible. Now these seem to have been relegated to the region of myths.”
Bellerophon, one of the major Greek heroes, possibly a doublet of Perseus, overcame the beast by the expedient of flying above her on Pegasus, the winged horse Perseus had unleashed from Medusa’s neck, and shooting her with his arrows.
The sphinx, another daughter of Typhon and Echidna, had the head and chest of a woman, bird wings, lion claws, and a dog’s body. She asked passers-by to solve a riddle. If they failed, she destroyed or devoured them. Oedipus got past the sphinx by answering her question.
Although she may always have been a hideous monster, later stories say Poseidon fell for a beautiful maiden named Medusa, perhaps an attendant of Athena. Unfortunately, the sea god chose to sate his lust in Athena’s shrine. Athena was outraged and turned the beauty into a hideous monster with snakes for hair. In this transformation, she could turn a man to stone with a single look. Even after Perseus (with Athena’s help), separated Medusa from her head — an act that allowed her unborn children (Pegasus and Chrysaor) to emerge from her body — the head maintained its lethal power.
Medusa is also counted as one of the Gorgons, three daughters of Phorcus. Her sisters are the immortal Gorgons, Eryale and Stheno.
Ovid, Metamorphoses 4. 770 ff (trans. Melville) (Roman epic C 1st B.C. to C 1st A.D.) :”[After slaying the Gorgon, Perseus travelled to the land of the Aithiopians (Ethiopians):] A chief, one of their number, asked [Perseus] why she [Medousa] alone among her sisters wore that snake-twined hair, and Perseus answered: ‘What you ask is worth the telling; listen and I’ll tell the tale. Her beauty was far-famed, the jealous hope of many a suitor, and of all her charms her hair was loveliest; so I was told by one who claimed to have seen her. She, it’s said, was violated in Minerva’s [Athena’s] shrine by the Lord of the Sea (Rector Pelagi) [Poseidon]. Jove’s [Zeus’] daughter turned away and covered with her shield her virgin’s eyes. And then for fitting punishment transformed the Gorgo’s lovely hair to loathsome snakes. Minerva [Athena] still, to strike her foes with dread, upon her breastplate wears the snakes she made.’”
The Harpies/Harpuiai (by name Calaeno, Aello, and Ocypete) — merely personified storm winds in Homer, but as fast as winds or birds in Hesiod — are insatiably hungry. Not only do they eat food that belongs to others, but they contaminate what they leave behind with their fecal matter. They appear in the story of Jason and the Argonauts. The blind King Phineas of Thrace is harassed by these bird-women monsters who pollute his food every day until they are driven away by the sons of Boreas to the Strophades islands.
The Minotaur was a fearful twiform composite, half-man and half-bull, and all cannibal.
He was born to Pasiphae, the wife of King Minos of Crete, who had an unusual affection for bulls. To prevent his stepson, the Minotaur, from eating his own people, Minos shut the Minotaur in a complex labyrinth, designed by Daedalus who had also built the contraption that had permitted Pasiphae to be impregnated by the white bull of Poseidon.
[3.1.4] But angry at him for not sacrificing the bull, Poseidon made the animal savage, and contrived that Pasiphae should conceive a passion for it.18 In her love for the bull she found an accomplice in Daedalus, an architect, who had been banished from Athens for murder.19 He constructed a wooden cow on wheels, took it, hollowed it out in the inside, sewed it up in the hide of a cow which he had skinned, and set it in the meadow in which the bull used to graze. Then he introduced Pasiphae into it; and the bull came and coupled with it, as if it were a real cow. And she gave birth to Asterius, who was called the Minotaur. He had the face of a bull, but the rest of him was human; and Minos, in compliance with certain oracles, shut him up and guarded him in the Labyrinth. Now the Labyrinth which Daedalus constructed was a chamber “that with its tangled windings perplexed the outward way.”
Book 3 of the Library of Apollodorus, Tran. by J. G. Frazer
To feed the Minotaur, Minos ordered Athens to send over 7 young men and 7 young women each year. Athens’ great hero Theseus volunteered for the sacrifice and to prove himself. With the help of one of the king’s daughters, Ariadne (half-sister of the Minotaur), Theseus maneuvered around the maze, slew the beast, and departed with Ariadne, whom he would soon abandon.
The Nemean Lion was one of the many offspring of half-woman and half-serpent Echidna and her husband, the 100-headed Typhon. It lived in Argolis terrifying people. The skin of the lion was impenetrable, so when Hercules tried to shoot it from a distance, he failed to kill it. Not until Hercules clubbed the beast senseless was he able to strangle it to death. Hercules wanted to wear the Nemean Lion skin as protection, so he took one of the Nemean Lion’s own claws to rip up the skin.
The Lernaean Hydra, one of the many offspring of half-woman and half-serpent Echidna and 100-headed Typhon, was also many headed. It was a serpent who lived in the swamps. One of hydra’s heads was impervious to weapons. Its other heads could be cut off, but then one or two would grow back in its place. The breath or venom of the Hydra was deadly and it ate animals and humans wherever it roamed.
Hercules (Herakles or Hercules) was able to put an end to the depredations of the hydra by having his friend Iolaus cauterize the stump of each head as soon as Hercules cut it off.
When only the head impervious to weapons was left, Hercules tore it off and buried it. From the stump, poisonous blood still oozed, so Hercules dipped his arrows in the blood, making them lethal, and ultimately, causing the death of the two good centaurs.
Polyphemus locked Odysseus and his men in a cave while he tended his flock and then returned to his cave home for dinner. Unfortunately for the survivors of the Trojan War, it isn’t sheep that Polyphemus fancied for the night’s repast, but man.
And so, it became incumbent on the warrior known more for his guile than his amazing archery skills to find a way to save as many of his men as possible.
Polyphemus is a giant, a cyclops, with one large eye in the center of his forehead. He is a son of the sea god Poseidon and immensely strong, but not immensely intelligent.
He enjoyed the wine that Odysseus plied him with and fell asleep. While in his drunken stupor, Odysseus and men jabbed his eye with a sharp stick.
Well, that didn’t do much good, since the blinded giant could still feel around in the cave for the next meal. They needed a way out, and it’s here that Odysseus’ cunning shines.
Odysseus arranged to have his men and himself strapped to the underbelly of the furry sheep. This way, as the furious giant checked for escaping food, by feeling the back of every animal that passed out of the mouth of the cave, he failed to notice the men hidden beneath.
Aristophanes, Plutus 299 ff (trans. O’Neill) (Greek comedy C5th to 4th B.C.) :
“We will seek you, dear Kyklops (Cyclops) [Polyphemos], bleating, and if we find you with your wallet full of fresh herbs, all disgusting in your filth, sodden with wine and sleeping in the midst of your sheep, we will seize a great flaming stake and burn out your eye.”