Here's my first contribution to spooky month.
The picture is done by cometpunk .
The idea is heavily inspired by DnD and Hasdur from the Chuthulhu mythos.

It's an idea I had lately. It's about a goblin girl from the forest. If you stay on her good side she is nice, cute and helpful and will guide you through the forest.
But if you hurt the forest or attack her and the other goblins in the forest she'll change into a way nastier and much more dangerous form.
Channeling the wrath and power of nature she turns into an inhuman or rather ingoblin creature to kill her opponents and use their bodies to fertilize the forest. Stories about her quickly spread to the nearby villages where the forest is then associated with an evil demon or some sort of eldritch nature god.