In Greek mythology, the Colchian dragon guarded the sacred grove of Ares where the Golden Fleece hung.
The dragon’s watch over the fleece forms the central obstacle in the Argonauts’ quest. King Aeëtes of Colchis kept the fleece in a grove sacred to Ares, and the creature was said to remain awake and vigilant. Jason could not simply overpower it, so Medea helped by using magic to induce sleep.
The fleece itself was the golden skin of the ram whose rescue had saved Phrixus. Its recovery became the mission that brought Jason and the Argonauts to Colchis. The dragon’s role as guardian gives the quest a final supernatural barrier after the heroes complete their other challenges.
This dragon is frequently confused with Ladon, who guards the golden apples of the Hesperides. The two creatures protect different objects in different locations. The Colchian dragon is also not the Hydra, whose many heads and regeneration belong to Heracles’ second labor.