If you are doing the Trials and come across one of these bad boys, deal with it quick. They tash, slow and as we found out, also MEZ. Im a level 65 paladin who resisted most of this mobs spells but once tashed found out the hard way that I CAN still be mezzed even with a base 150MR.
Doesnt happen often, but when it does, its a major pain.
-Bael