• Cerberus, the three-headed, giant hound that guarded the gates of Hades
  • Charybdis, a sea monster whose inhalations formed a deadly whirlpool
  • Empousa, a vampiric demon with a leg of bronze and a hoofed foot of a donkey; she seduced men in order to feed on their flesh and blood
  • Gorgons, cursed sisters with serpents for hair
    • Medusa, the sister capable of turning men to stone with her gaze
    • Stheno, the most murderous of the sisters
    • Euryale sister most known for her death-bellowing screams
  • Graeae, three old women with one tooth and one eye among them
    • Deino
    • Enyo
    • Pemphredo
  • Harpies, winged monsters with the bodies of chickens and the heads and torsos of women
  • Kobaloi, a species of mischievous creatures, fond of tricking or frightening humans
  • Mormo, a vampiric creature who bit bad children
  • Taraxippi, ghosts that frightened horses
  • Lamia, a vampiric demon which preyed on children
  • Hydra, a many-headed, water-dwelling, serpent-like creature that guarded an Underworld entrance beneath Lake Lerna. For every head that is cut off, two more grow back It was destroyed by Heracles, in his second Labour
  • Centaurs, a race of half-man, half-horse beings. Usually sons of Cronus.
  • Furies, the three Goddess' of pain. Worked for Hades in the Underworld to punish evil souls. Created from the blood of Uranus.
  • Nessus, a ferryman at the river Euenus
  • Pholus
  • Chimera, a three headed monster, with the foreparts of a lion, the middle-parts of a goat and goat's-head rising from its back, and a serpent-headed tail. Slain by Bellerophon
  • Hippalectryon, a creature with the fore-parts of a rooster and the body of a horse
  • Hippocampi, sea creatures with the fore-parts of horses and the tails of fish
  • Ichthyocentaurs, a pair of marine centaurs with the upper bodies of men, the lower fronts of horses, and the tails of fish
  • Ipotane, a race of half-horse, half-humans
  • Manticore, a monster with the head of a man, the body of a lion and the tail of a scorpion
  • Minotaur, a monster with the head of a bull and the body of a man
  • Ophiotaurus, a creature part bull and part serpent
  • Orthrus, a two-headed, serpent-tailed dog, slain by Heracles
  • Panes, a tribe of nature-spirits which had the heads and torsos of men, the legs and tails of goats, goatish faces and goat-horns
  • Satyrs and Satyresses, companions of Pan and Dionysus which had human upper bodies, the tails of horses, pug-noses and the ears of donkeys
  • Sileni, a race of elderly Satyrs
  • Sirens, three winged bird-women whose irresistible song lured sailors to their deaths
  • Sphinx, a creature with the body of a lion and the head of a woman
  • Telekhines, skilled metal-workers with the heads of dogs and flippers of seals in place of hands
  • Amphisbaena, a snake with two heads, one at each end of the body
  • Arion, the immortal horse of Adrastus
  • Balius and Xanthus, the immortal horses of Achilles
  • Calydonian Boar, a gigantic boar sent by Artemis to ravage Calydon and slain in the Calydonian Boar Hunt
  • Ceryneian Hind, an enormous deer which was sacred to Artemis; Heracles was sent to retrieve it as one of his labours
  • Chrysomallus, a flying, talking, golden-fleeced ram
  • Cretan Bull, the bull which impregnated Pasiphaë, resulting in the Minotaur
  • Erymanthian Boar, a gigantic boar which Heracles was sent to retrieve as one of his labours
  • Karkinos, a giant crab which fought Heracles alongside the Hydra
  • Laelaps, a dog destined always to catch its prey
  • Mares of Diomedes, four man-eating horses belonging to the giant Diomedes
  • Nemean Lion, a gigantic lion whose skin was impervious to weapons; it was strangled by Heracles
  • Pegasus, a divine winged horse
  • Phoenix, golden-red birds that could regenerate themselves or reproduce by bursting into flames and rising from the ashes
  • Stymphalian Birds, man-eating birds with beaks of bronze and sharp metallic feathers they could launch at their victims
  • Teumessian fox, a gigantic fox destined never to be caught
  • Agrius, a man-eating Thracian giant who was half man and half bear
  • Alcyoneus, the eldest of the Thracian giants, killed by Heracles
  • The Aloadae, twin giants who attempted to storm Olympus
  • Alops, a Sicilian giant, slain by Dionysus
  • Anax, a Lydian giant
  • Antaeus, a Libyan giant who gained strength from constant contact with the earth and wrestled to death all visitors to his realm until slain by Heracles
  • Argus Panoptes, a hundred-eyed giant tasked with guarding over Io
  • Chrysaor, a son of Medusa, sometimes said to be a giant
  • Cyclopes (Elder), three one-eyed giants who forged Zeus' thunderbolt, Hades' cap of invisibility, and Poseidon's storm-raising trident
    • Arges
    • Brontes
    • Steropes
  • Cyclopes (Younger), a tribe of one-eyed cannibalistic giants who shepherded flocks of sheep on the island of Sicily
    • Polyphemus, a cyclops who briefly captured Odysseus and his men, only to be overcome and blinded by the hero
  • The Hekatoncheires, the Hundred-Handed Ones, giant gods of violent storms and hurricanes.
    • Briareus or Aigaion (Βριάρεως), The Vigorous
    • Cottus (Κόττος), The Furious
    • Gyges (Γύγης), The Big-Limbed
  • Enceladus, one of the Thracian giants who made war on the gods; he was defeated by Athena and Heracles and buried underneath a mountain
  • The Gegenees, a tribe of six-armed giants fought by the Argonauts on Bear Mountain in Mysia
  • Geryon, a three-bodied, four-winged giant who dwelt on the red island of Erytheia
  • The Laestrygonians, a tribe of man-eating giants encountered by Odysseus on his travels
  • Polybotes, a giant who fought Poseidon during the Gigantomachy
  • Porphyrion, a giant who made war on the Olympians and was killed by Heracles. In Hesiod, he was king of the giants
  • Tityos, a giant slain by Apollo and Artemis when he attempted to violate their mother Leto.
  • Typhon, a monstrous immortal storm-giant who was defeated and buried underneath Mount Etna
  • The Colchian Dragon, an unsleeping dragon which guarded the Golden Fleece
  • Cychreides, a dragon which terrorised Salamis before being slain by Cychreus
  • The Ismenian Dragon, a dragon which guarded the sacred spring of Ares near Thebes; it was slain by Cadmus
  • Ladon, a serpent-like dragon which guarded the apples of the Hesperides
  • The Lernaean Hydra, a nine-headed dragon which guarded the springs of Lerna; it was slain by Heracles
  • Python, a dragon which guarded the oracle of Delphi; it was slain
  • Ethiopian Cetus, a sea monster sent by Poseidon to ravage Ethiopia, which was slain by Perseus
  • Trojan Cetus, a sea monster which plagued Troy before being slain by Heracles
  • Caucasian Eagle, a giant eagle set by Zeus to feed on the ever-regenerating liver of Prometheus; it was variously described as an automaton and a son of Echidna
  • The Hippoi Kabeirikoi, four bronze horse-shaped automatons crafted by Hephaestus to draw the chariot of the Cabeiri
  • The Keledones, singing maidens sculpted out of gold by Hephaestus
  • The Khalkotauroi, fire-breathing bulls created by Hephaestus as a gift for Aeëtes
  • The Kourai Khryseai, golden maidens sculpted to Hephaestus to attend him in his household
  • Talos, a giant man made out of bronze to protect Europa
  • Arimaspi, a tribe of one-eyed men
  • Hyperboreans, a mythical people who lived far to the north of Thrace
  • Monopodes or Skiapodes, a tribe of one-legged Libyan men who used their gigantic foot as shade against the midday sun
  • Panotii, a tribe of northern men with gigantic, body-length ears
  • Pygmies, a tribe of one and a half foot tall African men who rode goats into battle against migrating cranes