Spider Climb. The piercer can climb difficult surfaces, including along ceilings, without needing to make an ability check.
Bite. Melee Attack Roll: +3, reach 5 ft. Hit: 5 (1d8 + 1) Piercing damage.
Drop. The piercer falls. Dexterity Saving Throw: DC 11, one creature directly underneath the piercer. Failure: 10 (3d6) Piercing damage. Failure or Success: The piercer reduces any damage it takes from the fall by 20.
