Ophicus is an actual constellation between Scorpius and Sagittarius, not visible in the northern hemisphere (except only briefly in the Arctic and near the equator. The ancient Greeks associated Ophicus with the infant Apollo's successful defeat of the Python at Delphi and with the Trojan Laocoon, who warned his people about the Trojan horse and was strangled by sea serpents sent by Poseidon. The ancient Romans also associated the constellation with the healer Asclepius who learned some facets of healing from serpents.

Some astrologers consider Ophicus to be the 13th sign of the zodiac, situated between Scorpio and Sagittarius, but due to the precession of the equinoxes, today related to the time period November 29-December 18.