In Greek Mythology, the Colchis Bulls were created by the god Hephaestus, and were given to King Aeetes as a gift. They are made from bronze, their horns are sliver, and their eyes are rubies. When Jason came to Colchis in order to obtain The Golden Fleece, King Aeetes had him yoke the Colchis Bulls and use them to plough a field. The field was then to be sown with dragon's teeth. Jason managed to resist the burning flames of the Colchis Bulls due to a potion that was given to him by Medea.
Two Colchis bulls attack Camp Half-Blood, being able to pass by the camp's borders because Thalia’s Tree was poisoned. After Annabeth gave Tyson permission to enter, he raced to Percy Jackson and smashed the face in of one of the bulls. The other by the Camp's Border patrol led by Clarisse. They are later used by the Hephaestus Cabin to make the tracks for the Chariot Races.
- They are bronze, which makes them hard to damage.
- They can breathe fire (the only defenses are Medea's Sunscreen SPF 50,000, or being a creature immune to fire like cyclopes or certain children of Hephaestus who have immunity against fire, like Leo).
- Their skin is burning hot.
|Species:||Centaur | Cyclopes | Dragon | Drakon | Empousa | Giants | Harpy | Hyperborean Giant | Ichthyocentaur | Karpoi | Laistrygonian Giant | Pegasus | Skolopendra | Stymphalian Birds | Telekhine|
|Friendly Monsters:||Argus | Blackjack | Briares | Chiron | Don | Ella | Festus | Gleeson Hedge | Grover Underwood | Hippocampus | Mellie | Mrs. O'Leary | Ophiotaurus | Peleus | Scipio | Tyson | Tempest|
|Enemy Monsters:||Agrius and Oreius | Arachne | Basilisk | Charybdis and Scylla | Chimera | Chrysaor | Clazmonian Sow | Colchis Bull | Echidna | Euryale | Geryon | Joe Bob | Kampê | Manticore | Medusa | Minotaur | Nemean Lion | Polyphemus | Sphinx | Stheno | Typhon ||
|Neutral Monsters:||Cerberus | Erymanthian Boar | Gray Sisters | Gorgons | Furies | Flesh-Eating Horse | Gryphon | Hippocampus | Siren|