I just completed Dungeon of the Lizard priest in challenge mode using a party of only elves, and in the third battle there was no Lizardman Priest of any kind, be it Slub Gut or a placeholder. Although the quest text references dealing him a critical wound before he escapes, all I fought was one Lizardman Spearman and Two of the smaller lizards with nets (sorry, don't remember the name).
