I soloed this mob with EASE on a 64 necro. Root, dot, and re-root. Don't let root break or you will likely die. Rough estimate would be 12-15K HP. Spawns in tunnel very close to wizy spires.
Although I won't name my Guild, he appears to have 50-70k HP (from my logs, that's about what I counted, I think..) and flurries constantly, faster than Zerks. @_@ Left us STONE COLD until our three Clerics managed to rez our tanks, but by then he was getting nuked and crazy. Root/Snare failed on EVERY cast, nasty resists, barely any Fire and Magic nukes landed, and only four Necro DoT's landed, forgot which ones. Quads for 350 on a 900 AC Bard, and quadded for 280 on a 1300 AC Warrior. Talk about your bad luck...