the Ferryman
The Ferryman is a being in the Halls of the Dead who carries the dead across the river dividing the Halls of the Dead.
He must be paid a penny or he will not take you across the river. Any souls who cannot pay are left stranded on the shore for eternity and any souls who try to cross the river without the ferryman drown in the river for eternity.
References:
Pug and Tomas are taken of the river by the Ferryman in A Darkness at Sethanon.