It spent the whole fight attacking my pet's aura (Earth Strength Effect), which apparently has a lot of hitpoints. Assuming this is a bug. Very simple fight because of this, killed with Mage / Druid / Druid, all 70.
I saw this guy runnin at me from a distance so i started casting circle of nexus to save me and my bud, then all of a sudden he pops right on top of us and kills us both in 5 hits.
The mob was re-tuned in the 3/23/2004 patch. Instead of being lvl 50, having 32k HPs and hitting for 1993 it is now lvl 70, has many more than 32k HPs (closer to 100k) and hits for 1026 (799 with def/Stone).
The kicker is that he now randomly AE rampages so keep the casters/healers at a distance. He still summons but can be partially slowed.
I was just there on Xev today. THIS MOB IS NOW BELOW 63! He conned dark blue ready to attack to me as a 63 cleric. I wager the rest of that data has been retuned also. Too many high level mobs back then stuck where they didn't belong... like in OoT. He seems to be the pet of the ogre that inhabits the same island... He followed very dutifully after in stutter steps, though he is about 10 times taller than the ogre.