Dark Sun - Destiny and sacrifice
Silk wyrms are enormous armored serpents that fly through the olive sky above their prey. They coil and uncoil as they fly, as if moving through sand, using their psionic power of levitation to keep them in the air. They can reach up to 50 feet in length and have a hard segmented chitinous shell that covers their bodies. Silk wyrms spin their paralyzed victims into silk cocoons, which they slowly drain of blood over the course of days.
Trapped victims can linger for days in the coccons, unable to move and slowly being fed upon, before dying of dehydration and blood loss. The coccons,in turn, are highly prized in most city-states because of its fire resistance and is used in the manufacture of silk clothing.
The PCs encountered a silk wyrm at an oasis not far from fort Skonz. Pamak had intented it to be their grave, but they defeated the serpent.