Sometimes I feel like just putting actual Cthulhu in D&D kinda waters down the more "native" Lovecraftian elements of the game, like aboleths, slaadi, gibbering mouthers, Tharizdun, etc.. And no offense to Bruce Cordell, but I feel like the Far Realm has done a good bit of damage by sort of isolating cosmic horror from the regular multiverse and putting it all in one big impossible box. Have we truly lost the sense of wonder that going to other planes should evoke in us?
What are some of your favourite Lovecraftian elements of D&D that aren't just stuff directly from the Cthulhu Mythos?
In my own setting, I use the Far Realm as the source of psionic energy and the “anti-real”, with heavy inspiration from Terry Pratchett’s otherworldly dimensions. I think it works well in this case because I have a simple multiverse, rather than the Great Wheel which already has 7 planes full of scary monsters and evil energy.
I do agree with OP that Firestorm Peak and subsequent Far Realm canon has done some disappointing worldbuilding. It really waters down aberrations to try and explain the unexplainable and especially to trace them back to a common source.
With all that said! Here’s my favorite eldritch horrors and cosmic creatures of D&D:
Things that live on the Ethereal Plane and hunt in our world! It’s very Upside Down, very spooky to see living creatures that come from the ghost realm. There’s the Xill (intelligent parasitic bug aliens) and the Thought Eater (a psychic platypus skeleton) and the Ethereal Bros, Filcher and Marauder, who are kind of silly but a genuine menace to adventurers.
Mind Flayers. Overused? Maybe, but I love their whole lore of being from an inevitable doomed future and their inability to feel emotions without eating your brain.
The Sussurus, a strange creature made of living glass that eats air and kills undead. I think it would be cool to have a quest where you’re protecting a client from this mysterious thing, and then find out your client is a vampire!
I really like the kuo-toa lore about them inventing new gods and making the gods real. Are they just more powerful believers than anyone else? Or is there some pre-existing well of fishy deities that the kuo-toa can tap into when they need a new patron? What does that imply for, say, a human cleric of Mystra?
Idea: run a campaign that focuses on your favorite monsters from a particular category.
