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Bone Crawler

Huge aberration, neutral

Armor Class 16 (natural armor)
Hit Points 161 (14d12 + 70)
Speed 30 ft., climb 10 ft.

23 (+6) 16 (+3) 20 (+5) 9 (–1) 15 (+3) 9 (–1)

Damage Immunities poison, psychic; bludgeoning, piercing, and slashing from nonmagical weapons
Condition Immunities charmed, exhaustion, frightened, paralyzed, petrified, poisoned
Senses blindsight 60 ft., passive Perception 13
Languages Deep Speech
Challenge 13 (10,000 XP)

Special Traits

  • Spiked Bone Armor. The bone crawler is encased in a shell of ironhard bones that can absorb 150 hit points worth of damage. Against area of effect attacks, the bone crawler’s bone armor will still take damage regardless of whether the bone crawler succeeded on the save. If the bone crawler succeeds on the save, the armor takes half the total damage dealt by the attack. If the bone crawler fails its saving throw, the armor takes double damage from the area effect. For every 10 hit points of damage the armor takes, the armor gains an additional bone spike. A creature that starts its turn within 5 ft. of the bone crawler takes damage due to the bone spikes. For every bone spike the armor has accumulated, the adjacent creatures take 1d4 piercing damage. The bone crawler can repair its armor over a 24 hour period by absorbing additional bones into its hulking mass. As the bone crawler absorbs bones, it secretes a substance that will harden, coating the bones, and create the iron-hard shell. For every 3 hit points of bone absorbed by the crawler, 1 hit point of damage is repaired on the armor. For example, if the crawler absorbs the skeleton of a creature that had 75 hit points it would repair 25 hit points of damage on its armor.
  • False Appearance. While motionless, a bone crawler is indistinguishable from a mound of bones.
  • Improved Critical. The bone crawler’s bone blade attacks score a critical hit on a roll of 19 or 20.


  • Multiattack. The crawler can make up to 6 attacks using its bone blades and bone whips.
  • Bone Blade. Melee Weapon Attack: +11 to hit, reach 10 ft., one target. Hit: 17 (1d10 + 8) slashing damage.
  • Bone Whip. Melee Weapon Attack: +11 to hit, reach 10 ft., one target. Hit: 11 (1d6 + 8) bludgeoning damage.
  • Whirling Frenzy (Recharge 5–6). The bone crawler spins its bone blades in a swirling storm of sharpened edges. Creatures within 10 feet of the crawler must succeed on a DC 15 Dexterity saving throw, taking 15 (2d8 + 6) slashing damage on a failure, or half as much damage on a successful one.


Unarmored, the bone crawler is a fleshy disc-shaped lump approximately six feet in diameter, with a slightly concave top.

The bottom curves downward and ends with a circular mouth at its nadir. From the central mass sprout several dozen tentacles, each specialized to perform different functions: stubby muscular ones provide movement, thin graceful tendrils are tipped with sensory organs, and the long, limber whipfronds are used as a means of attack and manipulation. The flesh of a bone crawler ranges from olive green to slate grey to jet black.

When it is encased in bone armor, the bone crawler appears much different. When still, it resembles a 15-foot-diameter mound of bones, piled haphazardly together. A canny observer may note fleshy tendrils or roots webbed throughout the mass. Once it begins to move, the armored crawler is a whirling nightmare of interlocked bones forming a 15-foot-diameter central mass, with bony tentacles extending out from it in all directions.

The bone crawler is an unusual aberration that girds itself with hardened bones, fused together and manipulated by lenticular limbs called whipfronds, to serve as both a weapon and a defense.

Bone crawlers exist by attacking and killing just about anything they can come to grips with. They feast upon the flesh of their enemies, and then integrate the bones of their prey into their armor, repairing any damage sustained. Some bone crawlers have been known to seek out crypts and graveyards, exhuming bodies for their bones.

Section 15: Copyright Notice

Tome of Horrors © 2018, Frog God Games, LLC; Authors: Kevin Baase, Erica Balsley, John “Pexx” Barnhouse, Christopher Bishop, Casey Christofferson, Jim Collura, Andrea Costantini, Jayson ‘Rocky’ Gardner, Zach Glazar, Meghan Greene, Scott Greene, Lance Hawvermale, Travis Hawvermale, Ian S. Johnston, Bill Kenower, Patrick Lawinger, Rhiannon Louve, Ian McGarty, Edwin Nagy, James Patterson, Nathan Paul, Patrick N. Pilgrim, Clark Peterson, Anthony Pryor, Greg Ragland, Robert Schwalb, G. Scott Swift, Greg A. Vaughan, and Bill Webb