A zealot barbarian would indeed be the answer, being completely unkillable until they've been whittled down to 0 HP and their rage ends (as the moths can't grapple a level 20 barbarian even with a nat 20).
Ah, but that's the beauty of it... Barbarians get unlimited rages per day at level 20. So the rage never ends since you can always just extend it.
The grappling is a bit odd, since the trailer on the moth bite attack requires the player to make a DC13 (14 on the queen for some reason, but nothing else) "Strength Check".
This would infer that it's a straight ability check rather than a Strength(Athletics) check as with most grappling contests. It's also not a saving throw. This means (if I'm correct in believing you can't add proficiency bonus to straight ability checks) it
would still theoretically be possible for it to affect the barbarian. They'd just need to roll 5 or lower twice in a row (due to rage advantage).
If you
do get to add proficiency, then yeah... Only way they'd be able to get ya is with making an actual grapple attack and getting obscenely lucky with all the rolls. Then once they've got hold of you it's pretty much curtains, since being 0hp seems to be the only requirement (never mind the fact that Zealots are still perfectly fighting fit at that point), and your own physical prowess or stature is completely irrelevant to the DC17 strength check that THEY make.
But yeah. There's a lot to unpack here.
Anyways, have some more discussion salad from the same fellow:
Here's another clever idea I had for a trap, the party is walking around somewhere when suddenly they find themselves at the bottom of individual pit falls that weren't detected by a 10ft pole or any other such method of checking for the pitfall (the pitfall is from illusion magic) and are seemingly 10ft deep, the characters can't climb out or use magic or tools to climb out for some strange reason. (Wisdom save DC12 if anyone catches on to what's going on but if they roll blind without figuring out it's an illusion the DC raises to DC18.)
If deployed it's an option for creatures to attack the captured creatures with Advantage but if attacked and they decide to Roll Wisdom to figure it out they do so with advantage if they're composed but disadvantage if not composed, if they figure it out with or without the Wisdom Roll they gain advantage on the Roll against the Wisdom Save DC.
Any thoughts on this fun idea?
...what does that even
mean?Oh, yes, if anyone's wondering... The creative mastermind behind all this is purportedly 32 years old. So it's not, like, some 10-year-old kid just babbling about stuff going on in his hyperactive imagination.
Someone actually replied to the thread asking for links to the monsters since he was a "newbie" and couldn't find them... OP graciously supplied the links to these "Horrors of Fantasy Mad Science Run amok in all their deadly glory!", and cautioned the neophyte by saying "Try not to have nightmares..."
Yeah. 'Cause it's too late for me, dude.