These things are insane.....wtf. After killing Hendrak and his minions, surviving Iuz avatar and cleaning out utterly 4 levels of the temple, a group of 4 of the damn things ambushed me on my way back to Hommlet....no sweat I thought, I killed 2 earlier in the game when party was only 6th level.... they're level 10 now, I have a paladin, monk, bard, Druid, cleric, wizard and fighter, all with ACs over 25, very high BABs and premium gear and we were full strength and 4 vodyanoi mopped the grass with us. 2 members dead and the rest confused, I exited game when they got rest of my party down to like 10 hp. *sigh* and I hadn't saved in awhile. Idiot. Just had to vent.
It's the Gremlins. they lurk in your computer waiting for JUST such an occasion then temporarily alter the code so that things like that happen