“Cerberus. The Great Worm. As a dog who craves barking, then grows quiet as he snaps up his food, so are the foul faces of the demon Cerberus, who thunders over these souls.” — Virgil
Cerberus was the three-headed hellhound who guarded the third circle of Hell, Gluttony.
Found at the entrance to the third circle, it was the fourth boss fought in Dante's Inferno. Dante fought Cerberus in order to continue through the circle of Gluttony and defeated it by decapitating it's first two heads with the scythe and using his cross to make the middle head explode after being eaten. Defeating Cerberus earned the player the "The Great Worm"achievement/trophy.
Cerberus has a turtle like body covered in the cloths of a noble, human hands and three, blood red, worm/dragon/snake like heads with decayed teeth, a fish tail fin crest and instead of eyes three pairs of mini mouths.
As a guardian of Gluttony, Cerberus is able to consume an indefinite amount of matter, be it filth or souls. Because of its many mouths it can feed on more of its meals and then burp out the souls to fire at Dante. He can stretch out to bite with efficient damage.
Cerberus appears in the animated film much as he does in the game, but he is more active, marching across Gluttony and eating souls. In order to pass through Gluttony, Dante allows himself to be swallowed, where he then makes his way through the monster's bowels, eventually destroying the beast's heart causing him to spew out a large amount of blood.
In Greek mythology, Cerberus was an actual three-headed guard dog of The Underworld; the domain of the Greek god Hades. The child of the monster Typhon and Echidna, Cerberus allowed souls to pass without incident, but would block the way if the living tried to enter, or the dead to leave. Cerberus could be overcome however; he can be bribed with cakes, put to sleep with song or drugged food, or even (in the case of the hero Heracles) subdued and carried off by force.
The structure of the battle with Cerberus (the monster trapped in a corner, rarely moving from its place and killing heads one at a time), is similar to the battle with Cerberus in Devil May Cry 3: Dante's Awakening, and the many Cerberus hounds in the God of War games. Both games are similar in theme and gameplay to Dante's Inferno.
In "The Inferno", Dante places Cerberus as the guardian of the third circle of Hell. With his three mouths, Dante saw Cerberus as a beast that was synonymous with the sin of Gluttony. Virgil gets past Cerberus by throwing mud in his three mouths, temporarily choking him.
