I’m working on a scenario with spider riding goblins and forest denizens in it, and it struck me that there is no Evil Giant Spider soundset, nor some sort of Treant/Dryad/Force of Nature soundset.
Here are my suggestions for making them
Evil Giant Spider set
Skittering spider sounds when they move around
Disgusting Squealing for when they speak or attack or die or splatter.
Eggs hatching
Spider sounds for both small, medium and big ones
Some creepy ominous sounds/music/ambience for when you crawl through their spidernest underground or in some old forgotten temple/castle
etc.
And…
Force of Nature / Forest Creatures of foe and fay
Of course some tranquil forest ambience (like en Earth elemental, but maybe with more leaf rustling or something. Riverstreams maybe)
Some curious sounds like every bush and branch is watching.
Fairy/spirit sounds? Laughter, singing
Drayds both friendly and battle-ready.
Seperate animal sounds like bears, wolves, for when the forest denizens need assistance
Treant/Treemen sounds, deep, old, creaky voices, speaking forgotten languages or welcoming/warning travelers in their own, dull language.
Treemen moving sounds, like big heavy trees uprooting and stuff
And so on.