Cocytus is the lake of ice at the bottom of Hell, the ninth circle, where the traitors are held fast up to the point where shame appears, their teeth chattering like those of storks. It bears the name of a river of the world of the dead, which Virgil says is born from the tears of the statue of the old man of Crete. It divides into four zones of treachery: Caina, Antenora, Ptolomea and Judecca. At the bottom, the punishment is the cold, and not the fire.
Where It Appears
Quotes
so that three winds were moving from him: from there all Cocytus was freezing. With six eyes he wept, and through three chins the tears dripped and the bloody slaver.
Cantos XXXI to XXXIV: The Ice and Lucifer, Dante, describing the wings and eyes of Lucifer