Griegen
Griegen is a rare undead elite that can be found in the southwestern portion of Zul'Drak. He is another one of those one of a kind easy to spot elites since nothing else in the area uses the same model as him. For this reason you will not need to use a macro in order to find him. Just keep your eyes peeled.
As with the other rare elites, they have a spawn timer of 3 - 6 hours. I recommend farming areas around here and checking back every 10 - 15 minutes for Griegen to spawn. He has 8 different spawn locations, however his pathing is very small so you can do just a quick once over. If you need some tips of where to farm nearby, head over to my website's farming locations page by clicking here.
Griegen Spawn Locations and Video