Wraithwisps

When a powerful necromancer dies, his spirit can cling to existence as a Wraith. Lesser necromancers need help to go on existing. Masters often drag their apprentices into un-life in the form of mad half-shades called Wraithwisps. A Wraithwisp has roughly the same appearance as a Wraith—an ethereal figure wrapped in a cloak. However, only glimpses of the figure are seen—a shimmering hood, willowy tendrils of cloth, and two thin, grasping hands.

Wraithwisps retain only a fragment of personality, as they retain only a fragment of physical form. The part that remains is filled with the typical rage of Wraiths but is far more incoherent and unfocussed. Hating anything living, Wraithwisps attack on sight, grasping with their cold hands and choking the life from their victims.

Source
pg. 141
 * Warhammer Fantasy RPG 2nd ED -- Night's Dark Masters