Which creature is three headed in the odyssey?

In Homer's "The Odyssey," the three-headed creature is Cerberus, the guardian of the Underworld. While Cerberus does not appear directly in "The Odyssey," he is referenced in relation to the realm of Hades. He is depicted as a fierce dog that prevents the dead from escaping and the living from entering without permission. His presence symbolizes the boundary between life and death.