Note: This article discusses material that was once considered canon but whose canonicity is now questionable.
A Wraith is one of the more sophisticated units employed by the forces of the Necrons. These grotesque floating killers lack legs or body except for a serpentine spinal column, and float over the battlefield using anti-gravity technology like ghosts. Their wide, hunched shoulders support a leering, skull face and long, whip-like arms that wield Necrodermis scalpel blades for fingers and a nightmare array of surgical implements. Moving with unnatural fluidity, Wraiths are fearsome in close combat, often phasing in and out of phase with the space-time continuum like ghosts, thus granting them their Imperial sobriquet of 'Wraiths'. This phase shifting ability which is based on the standard Necron phasing technology that they use to travel across the galaxy allows Wraiths to avoid physical damage from weapons or to even move through solid objects. It has been suggested by certain Imperial savants that in ancient days before the War in Heaven the Wraiths were once Necrontyr murderers and psychopaths before their eternal entombment within their cold, metallic husks.
- Codex Necrons (3rd Edition), p. 19