Springjaw Centipede Swarm

Medium swarm of small constructs, unaligned

Armor Class 15 (natural armor)
Hit Points 6 (2d4+1)
Speed 30 ft.

3 (-4) 13 (+1) 12 (+1) 2 (-4) 7 (-2) 2 (-4)

Skills Stealth +3
Damage Immunities poison, psychic
Condition Immunities charmed, exhaustion, frightened, poisoned
Senses darkvision 60 ft., passive Perception 10
Languages understands the languages of its creator but can’t speak
Challenge ? (25 XP)


  • Transform. A creature attuned to the swarm can speak its command word to transform one or more of its five centipedes into jaw traps, reducing the swarm’s maximum hit points by 1; or transform one or more jaw traps back into centipede form, increasing the swarm’s maximum hit points by 1. Its statistics are the same in each form. Any equipment it is wearing or carrying isn’t transformed.
  • Jaw Trap. Jaw traps are affixed to the ground by the centipede’s mandibles. When a creature steps on a jaw trap, they must succeed on a DC 13 Dexterity saving throw or take 3 (1d6) piercing damage and stop moving. Thereafter, until the creature breaks free of the trap, its movement speed becomes 0. A creature can use its action to make a DC 13 Strength check, freeing itself or another creature within its reach on a success. This destroys the trap. Each failed check deals 2 (1d4) piercing damage to the trapped creature.
  • Swarm. The swarm can occupy another creature’s space and vice versa, and the swarm can move through any opening large enough for a Small insect.
  • Springsteel Chitin. The centipede is designed to pop back together quickly. A creature that is proficient with tinker’s tools, or another springjaw centipede, can use its action to repair a destroyed springjaw centipede in its current form.
  • Dull Camouflage. The centipede swarm has advantage on Dexterity (Stealth) checks made to hide in rocky terrain.


  • Bite (true form). Melee Weapon Attack: +3 to hit, reach 5 ft., one creature. Hit: 3 (1d4 +1) piercing damage.


Modeled after the forms of giant centipedes that roam the Under Dark, springjaw centipedes are multipurpose constructs designed by deep gnomes for scouting, hunting, and trapping intruders.

Constructed with earth-toned metals, springjaw centipedes are able to traverse the cavernous walls and ceilings of the Under Dark undetected, and are a favorite of deep gnome tinkers.

Three in One. Springjaw centipedes are uniquely designed with the ability to segment their body and mind into three separate constructs. While separated, the tinier components of a springjaw centipede are able to act as hunting traps, using several of its bladelike legs to latch itself firmly in the ground, and laying its body and remaining legs flat in wait for any unwary creatures to stumble onto its hidden form.

Though unintentional, these traps often act as alarms as well, as creatures that find themselves trapped by a springjaw usually can’t help but cry out in pain and surprise. When the separate sections of a springjaw rejoin, their minds integrate, giving the whole construct the memories of each of its component parts.

Springjaw Minefields. Drow and duergar hunters in the Under Dark have been known to seek out and deactivate springjaw traps to use for their own purposes. Hazardous “minefields” of springjaw traps can often be found around the prisons and slave pens of duergar and drow. Adventurers should be wary; where one springjaw trap is found, many more may be concealed nearby.

Section 15: Copyright Notice

Zargoth’s Tome of Familiars, Copyright 2021, Arcana Games, LLC.

Section 15: Copyright Notice

Zargoth’s Tome of Familiars, Copyright 2021, Arcana Games, LLC.

This is not the complete section 15 entry - see the full license for this page