Cerberos/Definition

A dog, better described as a hound, with either three heads (or fifty heads -- depending on different versions) which lived in Tartaros. The final labor of Heracles was to capture Cerberos and lead him to the world of the living, according to Greek mythology. Source: Elizabeth Vandiver, Classics scholar, authority on Greek mythology and Greek tragedy, including the Iliad, Odyssey, Aeneid, Homer, and Virgil. This definition is based on her course Classical Mythology for The Teaching Company.