Stirge Bolts
These +1 crossbow bolts are inscribed with runes around the tip. They are a potent weapon for guards, especially in long-distance battles. Once a Stirge Bolt is shot and makes contact, regardless of if it hits the intended target or not, it turns into a Stirge, as the monster. The Stirge is angry, and immediately attacks the nearest creature. If the bolt hits its target, in addition to the normal damage of the bolt, the Stirge automatically attaches, and may begin draining blood on its next round
These bolts are typically used sparingly, for two reasons. First, the Stirge do not change back into bolts, they simply fly off once they have eaten their fill. Second, the process of making Stirge Bolts requires the capture of a live Stirge to be bound into the dark, making these items understandably rare.
Moderate Transmutation; CL 11th; Craft Wondrous Item, animate object; Price: 8,000 GP