The Boatman is a creature of the Underworld, appearing in The Boatman scenario from Conquest of the Underworld, the second part of Heroes Chronicles.
The Boatman is the only one that knows where to find the gate between the first and second level of the Underworld. It is said that he will take anyone to the next level if they pay his price. When Tarnum passes through on his way to rescue Rion Gryphonheart's soul from the demon Jorm, the Boatman asks for an Orb of Inhibition, a powerful magical item that was recently stolen from him. As the first level of the Underworld is vast enough that he'd never find the gate on his own, Tarnum agrees to find the artifact.
Once Tarnum gave him the artifact, the Boatman agreed to let him and his men pass through to the next level.
Charon[]
In some fan-made works, his character is merged with that of Charon, the ferryman of the dead of Enroth from Might and Magic VI: The Mandate of Heaven.