This is really interesting, I hope more people comment.
I kind of have one. I can't tell if it's an actual lore or just something my bipolar priestess told me because she wanted to have an answer when I asked her if evil existed outside of human nature.
She told me of the stick men.
She said they were malicious spirits that dwelled in the nearby forest. When you look upon them, they look like sapling trees, dead and leafless even in the height of summer, but still rooted to the ground. At least while you're looking. When your gaze is elsewhere they creep closer to you, surround you, until it is too late.
She discouraged me from wandering the deep wood and threatened to bury me to my neck in salt just for thinking about them, lest my interest summon them closer to town.
There's no record of these creatures as folk lore anywhere that I can find, and their description is vague and tropey enough she probably just made it all up.
Probably.