The material below is Open Game Content
Hit Dice: 16d8+64 (136 hp)
Speed: 30 ft. (6 squares), climb 20 ft.
Armor Class: 28 (–1 size, +3 Dex, +16 natural), touch 12, flat-footed 25
Base Attack/Grapple: +12/+22
Attack: Bite +17 melee (2d6+6)
Full Attack: Bite +17 melee (2d6+6) and tail sting +12 melee (2d6+3 plus poison)
Space/Reach: 10 ft./5 ft.
Special Attacks: Improved grab, poison, trilling
Special Qualities: Darkvision 60 ft., tremorsense 60 ft., vermin traits
Saves: Fort +14, Ref +8, Will +6
Abilities: Str 23, Dex 16, Con 19, Int —, Wis 12, Cha 4
Skills: Climb +14
Environment: Any land or underground
Organization: Solitary, pair, or pack
Challenge Rating: 12
Treasure: 10% standard
Alignment: Always neutral
Advancement: 17–32 HD (Large); 33–48 HD (Huge)
Level Adjustment: —
This creature looks like a massive centipede with a bright, reflective silver carapace. Its legs are dull silver and its oversized mandibles are black. A dull black stinger is located at the rear of its body.
Chain worms are subterranean predators with an insatiable appetite for meat. The creature has a particular fondness for dwarf, gnome, and bugbear flesh. Chain worms often build their nests near communities of these creatures so their food supply is readily available. Though not particularly fond of cold or damp weather, a chain worm can be found just about anywhere as its chitinous body offers it ample protection against less than friendly environments.
A chain worm’s nest is a hole or tunnel littered with rocks, bones, refuse, and debris, and often located on a rocky outcropping or ledge making it inaccessible to most creatures. Any valuables found in its lair are simply the remains of a previous meal that the chain worm couldn’t digest or didn’t bother eating.
Chain worms stand nearly 6 feet tall and are about 10 feet long with silver carapaces and dull silver legs. Their heads sport oversized dull black mandibles that constantly drip brownish-gray saliva. Its tail stinger is about a foot long and black (as it ages, its tail stinger changes to dull gray).
A chain worm lies in wait for a meal, attacking whenever its target comes within range. It attacks using either a nasty bite or by curling its rear body forward and stinging with its tail stinger. If a chain worm grabs a foe in its mandibles, it holds it and repeatedly stings it until it is dead.
Improved Grab (Ex): To use this ability, a chain worm must hit with a successful bite attack. It can then attempt to start a grapple as a free action without provoking an attack of opportunity. If it wins the grapple check, it establishes a hold and bites. A chain worm can deal automatic bite damage each subsequent round the hold is maintained.
Poison (Ex): A chain worm delivers a debilitating poison with a successful tail sting. The save DC is Constitution-based.
Chain Worm Poison: Injury, Fortitude DC 22 negates; initial and secondary damage 2d4 Constitution.
Trilling (Ex): By rapidly vibrating its carapace, a chain worm emits a high-pitched trilling sound that stuns and deafens all creatures within range. All living creatures within 30 feet that hear it must succeed on a DC 22 Fortitude save or be stunned for 1d4 rounds and deafened for 1 day. The save DC is Constitution-based.
Tremorsense (Ex): A chain worm can automatically pinpoint the location of anything within 60 feet that is in contact with the ground.
Skills: A chain worm has a +8 racial bonus on Climb checks and can always choose to take 10 on a Climb check even if rushed or threatened.
This material originated in a third party source (License).