General themes would be dark earthy tones like greens, browns, and blacks
Some key symbols/objects being bones, plants (especially any that are NOT a flower, such as Ferns), moss, dead leaves, and fungus
Animals/insects such as Slugs, snails, moths (not really butterflies as most butterflies are brightly colored and the key is dark neutrals and earth colors), and basically any animal that is not really "loved". Opossums, rats, toads, worms, etc
Like Fairycore's emo cousin ig
I've heard of Mosscore, Goblincore, and Forestpunk, but I am not sure if those would be correct, or if there are any others that are closer matches.
Thanks!