Prowler

Like bark bent into human form, the legends name it Ulth-Sha’korr, “Walker Between Roots” and warn that it appears only after the forest has been addressed improperly: a tree cut without offering, a stone overturned that should have remained dreaming. Other, darker legends say its purpose is mere cruelty.

Some believe it is the deliberate construct of some arcane science of the underworld, ancient tree-matter braided with living organs, its intelligence entering and withdrawing from the body in intervals governed by unknown principles. When it emerges, a single explorer is seized and removed, deposited far away and utterly alone.

The Prowler cannot be killed. When damaged sufficiently, it stiffens, calcifies, and resumes the posture of an ordinary tree. There it waits, until the forest is again disturbed and the lesson must be repeated — or until there is another opportunity to toy with mortals.