Armor Class 15 (natural armor)
Hit Points 22 (3d8 + 9)
Speed 5 ft., climb 5 ft.
Skills Stealth +5
Senses blindsight 30 ft., darkvision 60 ft., passive Perception 8
Languages —
Challenge 1/2
False Appearance. While the piercer remains motionless on the ceiling, it is indistinguishable from a normal stalactite.
Spider Climb. The piercer can climb difficult surfaces, including upside down on ceilings, without needing to make an ability check.
Drop. Melee Weapon Attack: +3 to hit, one creature directly underneath the piercer. Hit: 3 (1d6) piercing damage per 10 feet fallen, up to 21 (6d6). Miss: The piercer takes half the normal falling damage for the distance fallen.
Monster Manual (2014), p. 252