THE CIRCLE OF LIGHT
Bone Sprites are simply skeletal or cadaverous windlings. It is very rare for undead to arise amongst the windlings (some might claim impossible) but when Parlainth reappeared, it happened. Bone sprites are particularly evil undead. They would rather flee than fight the living. Unfortunately, these tiny undead are often the thralls of some greater creature using them to spy out location of their next attack.
Bone Sprites are especially horrifying to living windlings. Their joyless and endless existence, often as slaves of Horrors, horrifies the usually cheerful Windlings. Most Windlings believe that destroying a Bone Sprite is granting the poor creatures release, so they are usually particularly dedicated to this goal.