Horrus the Nightstalker

Horrus the Nightstalker, Rage of the Damned, is a Unique found in the Weeping Hollow in  of Diablo III.

In combat, it has Missile Dampening and Electrified affixes. Interestingly, its Missile Dampening dome will not activate until Horrus is in combat, so the first shot can be delivered as normal.