Said this before but had it filed as a duplicate mistakenly, so I'll say it again.
Health and damage potions have opposite effects on undead mobs. Thats fine. I understand this is not a bug.
But poison and regeneration potions have no effect on undead mobs.
They should have some effect. I don't care if it is positive or negative, but they should do something.
Still WAI. Still a dupe of MC-10168