Tunnel Worm

Tunnel Worm

This massive creature is a 30-foot-long, sleek black centipede with segmented armor covering its body. Its huge mandibles are serrated and razor-sharp. Heavy plates of chitin protect its oversized head.

Tunnel Worm

XP 3,900 ()

Unaligned Huge

Initiative +1


AC 16 (natural armor)

hp: 115 (11d12 + 44)

Saving Throws: Con +7

Resistance: Bludgeoning, piercing, and slashing damage from nonmagical weapons


Speed: 20 ft., burrow 20 ft.

Melee Attack—Bite: +8 to hit (reach 5 ft.; one creature). Hit: 3d8 + 5 piercing damage and the target must make a DC 16 Dex saving throw or be grappled.

Melee Attack—Severing Bite: automatic hit (one creature already grappled by the tunnel worm at the start of the tunnel worm’s turn). Hit: 4d10 + 5 slashing damage and the target’s armor class is reduced by 2. A successful DC 15 Dex orStr saving throw reduces damage by half and reduces armor loss to 1. Armor reduced to AC 10 is destroyed. If the target isn’t wearing armor, its armor class is not affected in any case.


Str 20 (+5), Dex 13 (+1), Con 19 (+4),

Int 1 (–5), Wis 8 (–1), Cha 4 (–3)

Languages: Common

Skills: Perception +5, Stealth +4

Senses: Tremorsense 60 ft.


Armored Skull: Only the tunnel worm’s head has resistance to bludgeoning, piercing, and slashing damage. Attacks against any other portion of its body aren’t affected by that resistance.



Organization: Solitary or cluster (2–5)

The tunnel worm is a burrowing creature related to certain other enormous, monstrosities (the monstrous centipede, the purple worm). It can sustain itself by scavenging, but it is a very aggressive predator and hunter. Its preferred food is fresh, raw meat.

Tunnel worms attack anything that enters their territory. They live in winding, disorienting complexes of 3-foot-wide tunnels that they’ve chewed through earth and stone. These burrows are often filled with the rotting remains of past prey; the worm’s offspring incubate in carrion.

The favorite tactic of the tunnel worm is to lurk in a spot where one of its tunnels passes very near a dungeon passage until it senses live prey passing nearby. Then it cuts through the last remaining bit of wall, snatches a creature, and retreats into the tunnel so that only its well-armored head is exposed to attack. Thus protected, it chews through its prey’s “protective covering” before devouring the gooey portions inside.

A tunnel worm that has lost more than half its hit points retreats to its lair if possible, taking along anything it’s grappled. If it can’t retreat, it fights to the death.

A typical tunnel worm is 30 feet long, but they’ve been known to grow to a length of 60 feet.