Nur Abath, Crest of Xol
From Destinypedia, the Destiny wiki
Nur Abath will behave like a typical Ogre in combat, using a highly-damaging stream of Void eye blasts from a distance and slamming the ground during close combat, and will occasionally summon lesser Hive units as well as Shriekers to aid it. However, it will be surrounded by a transparent aura, which will grant itself an immunity shield whenever another Hive unit walks into it. To remove this shield, all the Hive that are within the aura must be killed and other reinforcements need to be kept out.
Upon defeat, Nur Abath has a small chance to reward the IKELOS SG v1.0.1 shotgun.