I was clearing Crumbled Sanctuary and this popped up as the middle spawn in the bottom three spawns. Pretty badass mob, was a little unexpected. He hit fast and hard, but if you are ready for it should be no problem in GoD or better gear.
This nice fella also inhabits Ikkinz, Chamber of Destruction (Glorification Trial) and dropped a Dusty Mudstone of Life (HP +35 Augment Slot 8 only; Arms, Wrist, Hands, Feet, Waste).