The soul, Vanni Fucci, being punished for stealing makes an obscene gesture directed to God. This provokes all the snakes to swarm around his body and neck, paralyzing him. Immediately a centaur appears covered with snakes and a fire-breathing dragon on his back, to torment Fucci further. In an incredible scene, two other sinners appear, one as a man, the other as a lizard-like reptile.
A stunned Dante watches as these two sinners gradually and painfully transform and merge into one horrible monster. Next, another sinner in the form of a snake attacks a soul in the form of a man, causing their forms to slowly transform into the other, snake becomes man, man becomes snake.
Dante and Virgil then continue into the flames of Hell.