Apollo and Python. According to the Homeric Hymn, Apollo descended from Mount Olympus and chose the site of Delphi for the location of his oracle. He laid out the foundations of his temple, and at the spring nearby he slew a female dragon. The spot was called Pytho (from the ancient Greek pytho, “to rot”) because the sun’s rays caused the carcass to rot, and the god was given the epithet “Pythian” Apollo.
Other versions of the story credit Apollo with killing a male dragon, or serpent, called Pytho or Python. According to Ovid, Apollo killed a serpent that sprang from the stagnant water remaining after a deluge sent by Zeus. In some accounts the serpent was a son of Gaia. In others it was sent by Hera to persecute Leto while she was pregnant with Apollo and Artemis; as soon as Apollo was born, he killed the serpent.
Apollo slaying Python, who is usually represented as a serpent rather than a dragon, is a popular theme in the visual arts of all periods. The story in which the infant Apollo kills the serpent is often shown in classical vase painting.

Classical Sources. Homeric Hymns, “To Pythian Apollo” 281-374. Pindar, Pythian Odes 3.1—67, 9.1—70. Ovid, Metamorphoses 1.437—49. Pausanias, Description of Greece 2.7.7, 2.30.3-33.2