Ah, 'Cerberus'! Couldn't you feel a little chill just at the mention of his name? Cerberus, often associated with Greek mythology, is indeed considered a hellhound. He guards the gates of the underworld, making sure the dead souls don’t escape and the living can't sneak in. With his three heads—some depictions even show snakes growing from his body—Cerberus lives up to the terrifying image of a hellhound. But despite his fearful job, here's an interesting fact: Hercules had once tricked him into becoming a house pet for a short time in one of his twelve labors.