Phlegyas was a villain in the video game Dante's Inferno, being the boss of the fifth level of Hell, Anger, and the Ferryman of the River Styx.
Phlegyas was the son of Ares, the God of War. Phlegyas was killed off by Apollo, the God of the Sun. After he was killed, Phlegyas was turned into a Demonic Giant and condemned to the fifth circle of Hell. He was sent to Hell as a punishment for burning down the Apollonian Temple of Delphi.
Dante encountered Phlegyas when he unknowingly rode across the River Styx on the wrathful Demigod's crown. After successfully fighting his way towards Dis, and seeing Beatrice become the bride of Lucifer, Dante took control of Phlegyas and used him to break into the City of Dis. When Dante reached the circle of Heresy, Phlegyas broke the ground Dante stood on. Dante managed to jump out of the way just in time, but Phlegyas broke through the floor, plummeting into the Abyss.
Phlegyas is a gigantic Demon, largely made out of stone, and has strength matching with his stature. Besides this strength, he is also capable of breathing fire.