These minor war engines were commonly used by the forces of the Archenemy, originating with Urlock Gaur's Blood Pact. They resemble Defilers, but have much less armour, armament, and a living pilot who is hardwired into the cockpit. Accordingly, they are used in support of the infantry.
Based on Dave Taylor's amazing conversion http://davetaylorminiatures.blogspot.com/2009/03/completely-menacing.html and a fantastic sketch from Dan Abnett's Sabbat Worlds Crusade.
