Staff of Shadows, a difficult staff to find since the Quality level is so low that most of the monsters who would drop this Unique aren't of high enough level to drop a Long Staff. And the ones that are will much more often drop the Immolator or Naj's Puzzler, with their higher Quality levels. Fortunately, no one really wants to find this staff anyway except for collectors who find it amusing to find and keep the rarest Unique equipment.