A slow, stupid creature that crawls onto people and latches onto them, often on feet, hands, and other extremities, numbing down the area and slowly feeding on it. It's easy to avoid while awake, but nearly impossible to remove once attached. Many an adventurer has been forced to hack off an arm or leg after waking with a Stoneleech wrapped around it. Sleep with one eye open! (This idea came from "Wizard's Rule")
As the players travel along the trail, they notice a bear in the woods, following thier moves. It does not make any agressive moves, but neither does it leave. As daylight fades, the players need to decide what to do. Is it a spirit guide, or gaurdian to the forest; is it a lycanthrope, or being controlled by evil spirits; or is it just a curious bear?