Possible Clues:

• He ferries dead over Styx
• Boatman across the river Styx
• Ferryman on river of Hades
• Ferryman on Styx; anchor (anag.)
• Ferryman for the river Styx
• Underworld figure
• Pluto’s largest satellite
• Soul transporter
• In Greek myth, ferryman of Hades
• By the sound of it, there's just one chair on to get you over the sticks