Sneaky bastards, the lot of them
Some sovereigns prefer a different sort of tax from their subjects - whether freely given, or taken by force.
A dreamer is one who can only find his way by moonlight, and his punishment is that he sees the dawn before the rest of the world
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")