Originally Posted by
Araelus
SE has shown they can be far crueler than we can imagine. Then again, as the old saying goes, "don't give the DM ideas".
"There are three spine monkeys in the room."
"Is that like a monkey that rips your spine out?"
"No, they have quills on them, like a porcupi- Wait. Yes, you're right. And it gets stronger the more spines it attaches to itself from your party members."
OT: More weirdly aggroing mobs like 'phuabo and 'yovra or mobs with strange behaviour like 'hpemde would be interesting. Sea is a great example of strangeness that's interesting instead of irritating.
Maybe monsters who have a casting pattern that changes based on what JAs you use, or mobs that phase in and out (similar to 'grah aggro/non-aggro but in terms of whether they can be interacted with or not), or maybe more "aura" effects like the SCNM bosses.