Let’s compliment a story about a creature I made from scratch with a story about a creature I used exactly from the book. Exactly.
The grodair has a few similarities to the death slaad. They’re both owned by their respective companies, they’re both weirdly extraplanar but tend to hang out on the Material Plane, and my spellcheck hates both with a burning passion. But the grodair is significantly lower-level. It’s a tentacle-fish that can absorb water and release it at some opportune later time, allowing it to make a small home wherever it wants or slightly inconvenience opponents by making the ground muddy. It’s not actually that interesting in combat, but it does have this gem in its creature description:
A grodair is intelligent, but extremely absentminded and careless. Its memory is poor, and it has difficulty remembering things it was told even 5 minutes prior—though it can recall some events of the distant past with perfect (and often frustrating) clarity.
I introduced a grodair named Pechora to my players during their ocean-traveling campaign, where an NPC warily described it as a fish he knew who could act as a guide. The players assumed it was going to be like the map fish from The Legend of Zelda: The Wind Waker. Instead they got conversations like this:
Player: Alright, we need to find the cave where the monster is hiding. Pechora, do you know about the cave?
Grodair: What cave?
Player: The one where the monster is.
Grodair: What monster?
Player: The demon we’re tracking.
Grodair: What about it?
Player: Where is it hiding?
Grodair: Where is what hiding?
Player: Pechora. Do you know about the cave at which we can find the monster who has been attacking boats?
Grodair: Yes. We had a conversation at his cave one hundred twenty years ago, on a sunny Thursday.
Player: Great, finally. Where is it?
Grodair: Where’s what?
I’d like to say this taught my players a valuable lesson about asking the questions to which they want answers instead of asking something similar and assuming other people understand their meaning, but that’s not even a little true. It also did not teach the players not to go to the grodair for help. Because they spent the campaign apart from any sort of information network and without a means to call for help, I gave them an NPC sage who could answer questions about monsters for them. Because the NPC was helpful, they immediately assumed it was an enemy plant, even though they didn’t assume that about anybody else who was assisting them. Instead they opted to deal with the insufferable fish rather than the NPC who wanted to help because the fish was exactly frustrating enough to be trustworthy.
I mean, at the time, they were right, and the sage was an enemy plant. But the myth arc has since changed, and I retconned the NPC into a decent and upstanding guy, so who’s unreasonable now?
The moral of the story is that any one element of a monster, taken up to eleven, can make it memorable. It’s kind of the inverse of the death slaad, where one trait turned down to zero does the same thing. The grodair’s combat stats were completely irrelevant, and it could have been literally any person or creature with the same trait (take a drink). All that mattered was the little seed of “long-lived, absent-minded eidetic” to give the players an ally they regretted for years to come.