Jaculus

A Jaculus is a slender serpent that coils in branches and launches itself like a living javelin. Its scales match bark, and the first sign of its presence is often a straight puncture through cloth or hide. Once grounded, it climbs, waits, and chooses another line through the canopy instead of pursuing prey. Several may occupy one tree without moving until the same instant.

Living Javelin: piercing, 40 ft, +4 to hit, 1d6+2. If it began the round above its target, the strike deals an additional 1d6 damage.

No Second Cast: after Living Javelin, the Jaculus lands on the ground and loses 2 AC until it climbs again. Shaking or cutting its branch before it attacks spoils the launch.