Wraiths are entities of black shadow and darkness, that saps the life force of its victims with the grave's own chill. Wraiths have a special connection to shadow and darkness, and the light of the sun banishes them. They also have the ability to create spawn.
Wraiths hold no resemblance to what they were in life. Rather, they appear as creatures of pure shadow and darkness, hooded reapers of a vaguely humanoid shape.
Wraiths first appeared in the OD&D white box set, where they are described as tougher wights. This connection to wights was maintained in 1e, though the picture of the wraith was one of a creature of shadow, and they were described as having strong ties to darkness. Staring in the D&D Basic Set, they became creatures of shadow, which was further reinforced in later editions.