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")
Imagine that all the humanoid and demi-human laguages are actually the same, but pronounced with outrageous accents and bizarre idiom. All the elves have a French accent, all the Dwarves have Swedish, Dragons have a Pakistani accent...