- Neogi (as a substitute for the mi-go)
- Mind Flayers (substitute for the Primordial Ones)
- Grill & Grick (as a unified hive species or mi-go substitute)
- Slaad (substitute for Deep Ones)
- Gith (substitute for Space Aliens)
CARCOSA IS BETTER WITHOUT LOVECRAFT
D&D has its own set of strange creatures that could function as good substitutes as any Lovecraftian horror they are inspired by and, when placed together, offer an equally strange, dangerous, and morally questionable environment for the humans to move around in.
You really don't need much except a map, creatures, a rule system, and a goal. And since this little idea has infected my brain I m...