In a similar vein the Penumbra Fantasy Bestiary has the Halperthian Rattler and the Castigoran Constrictor, two of my contributions.Iron Cobra for the snake fakeout.
If I were putting yuan-ti & nagas in the same dungeon, I think due to their antagonistic lore that would be the main theme of the dungeon – it would either be a naga captive of the yuan-ti in a yuan-ti dungeon with its spiral-winding pillars and lack of stairs OR it would be a naga's lair (i.e. the dungeon with the McGuffin it is guarding) being invaded by yuan-ti that act as a rival party to the PCs.What are some snake-themed monsters? Constrictors and vipers, obviously. Naga, yuan-ti, medusa, couatl? What are some others? How would you fit them all into a dungeon while making sure each encounter has a distinct hook to set it apart?
Wouldn't that be a snakeout?Iron Cobra for the snake fakeout.