Large elemental, neutral

Armor Class 15 (natural armor)
Hit Points 76 (8d10 + 32)
Speed 30 ft., burrow 20 ft.

20 (+5) 12 (+1) 18 (+4) 4 (-3) 13 (+1) 11 (+0)

Condition Immunities prone
Senses darkvision 60 ft., tremorsense 60 ft., passive Perception 15
Challenge 7 (2,900 XP)

Special Traits

  • Crystalline Mandibles. The caterprism’s mandibles ignore resistance to slashing damage. In addition, when the caterprism attacks a creature with at least one head with its bite attack and rolls a natural 20 on the attack roll, it cuts off one of the creature’s heads. The creature dies if it cannot survive without the lost head. A creature is immune to this ability if it is immune to slashing damage, doesn’t have or need a head, has legendary actions, or the GM decides that the creature is too big for the head to be cut off with this attack. Such a creature instead takes an extra 27 (6d8) slashing damage from the hit.
  • Tunneler. Caterprism can burrow through solid rock at 5 feet per round leaving a 5 foot-wide, 8-foot-high tunnel in its wake.


  • Multiattack. The caterprism makes one bite and two claw attacks.
  • Bite. Melee Weapon Attack: +8 to hit, reach 5 ft., one target. Hit: 14 (2d8 +5) slashing damage. If the caterprism scores a critical hit, it rolls damage dice four times, instead of twice.
  • Claws. Melee Weapon Attack: +8 to hit, reach 5 ft., one target Hit: 16 (2d10 + 5) slashing damage.
  • Crystal Breath Recharge (5-6). The caterprism spews forth a crystalline silk-like substance in a 30-foot cone that instantly hardens into razor-sharp crystalline spears. Each creature in that area must make a DC 15 Dexterity saving throw, taking 28 (8d6) piercing damage on a failed save, or half as much damage on a successful one.


A large collection of items rises, forming into a swirling chaos that is the body of this being. The items move about throughout its bulk, somehow not touching one another in their mad dance.

A caterprism is from the Elemental Plane of Earth. It resembles a caterpillar made of crystal with hexagonal body segments and twelve sharply angled legs. Each body segment is about 2 feet long and contains a single pair of legs. The head of a caterprism is caterpillarlike, with large faceted eyes and huge mandibles.

Although caterprisms prefer to consume the rich minerals of their home plane, they sometimes wander through natural portals into the Material Plane. There, they create long, winding tunnels as they eat their way through the solid rock. Dwarves have been known to bring caterprisms under some degree of control, using them to help carve out new mines and dwelling places. If it feels threatened, a caterprism’s first action is to shoot at its opponents with its crystalline silk-like secretions. It then closes to bite, or rears up and stabs at opponents with the first two of its razorsharp legs. A caterprism can eat through 1 foot of solid stone per minute, leaving behind permanent tunnel 5 feet in diameter.

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