In Greek mythology, Charon was the ferryman of Hades, which took the newly dead across the river Acheron (or Styx) if they could pay for the ride. A coin to pay Charon for passage was placed on or in the mouth of the dead person. Charon is also the largest moon of Pluto or one member of a double dwarf planet with Pluto being the other member, depending on the definition taken into consideration.