It had been reported that a few mobs are no longer tagged as undead even that they were undead before the big NPC type revamp. Wall of Slaughter: a murkglider licheglider a murkglider soulstalker a murkglider spiritsipper Ruins of Lxanvom: https://everquest.allakhazam.com/db/npclist.html?zone=174 (check mobs tagged as undead) Puslings might be undead too (they do look like ghouls)
That was fast. Now I stumbled about another dissonance which is the "a scrounging rat". It is tagged as undead as your undead slow spell does show. I will just quote myself from the other thread:
