Hesiod's Theogony places Cerberus within a whole family of monsters born to Typhon and Echidna, siblings that include Orthus, the two-headed hound who guards Geryon's cattle in a separate labour of Heracles, the multi-headed Lernaean Hydra, and the fire-breathing Chimera, so that the Twelve Labours as a group amount to Heracles working his way through nearly one monstrous family's entire membership rather than facing a series of unrelated dangers.
Cerberus's later literary afterlife is dominated by Dante. In the sixth canto of the Inferno he guards the third circle of Hell, where the gluttonous lie in freezing mud and filth, and Dante gives him a grotesquely physical presence, three canine heads, clawed hands rather than paws, and a belly he uses to flay the damned, closely modelled on the classical hound but recast entirely within Christian punishment. Virgil, as Dante's guide within the poem, pacifies the beast by throwing fistfuls of earth into its three mouths, a direct medieval echo of the honeyed, drugged cake the Sibyl uses to quiet Cerberus in the Roman Virgil's own Aeneid, so that one ancient poet's trick for getting past the hound becomes, centuries later, a scene within another poem in which Virgil himself repeats it as a character.