Xylaria polymorpha, commonly known as dead man’s fingers, is a saprobic fungus. It is a common inhabitant of forest and woodland areas, usually growing from the bases of rotting or injured tree stumps and decaying wood. It is characterized by its elongated upright, clavate, or strap-like stromata poking up through the ground, much like fingers.
It doesn’t sound very creepy if you just read the description above and maybe many of the photos you saw before don’t look like that creepy, especially when they grow in cluster. However, at some circumstance, when only several (like 3 to 5) of “fingers” arise from the ground, the only reaction I can have probably is to sprint the other way and call the police. Don’t believe me? Just check it out!