Updated flavor text. Moving on...
DIOPATRA
FREQUENCY: Rare
NO. APPEARING: 5-50
ARMOR CLASS: 8
MOVE: //9. (3.)
HIT DICE: 2-10
% IN LAIR: 98%
TREASURE TYPE: Jaws (see below)
NO. OF ATTACKS: 1 grasp, then 1 bite per round
DAMAGE/ATTACK: 1-8 or 1-4, then 1-6 per round
SPECIAL ATTACKS: Grasping; surprise on 1-4 from tunnel
SPECIAL DEFENSES: Nil
MAGIC RESISTANCE: Standard
INTELLIGENCE: Non-
ALIGNMENT: Neutral
SIZE: L (2-4. diameter; 12-25. long)
PSIONIC ABILITY: Nil
The Diopatra has a much more complex jaw apparatus than does the Nereis, having both upper and lower sets of jaws. The upper jaws consist of a pair of pincers with subsidiary shearing jaws. The upper jaws work as a single unit: If the upper jaws make a successful roll to hit prey, they hold the prey steady while the shearing jaws rip into it to hold the prey in place for the lower jaws to work. The upper jaws cannot chew. The initial attack by the upper jaws is made at +4 against all armor types rated as bulky or fairly bulky because of the speed of the worm. Damage is only 1-4 hp against such heavily armored prey, however, compared to 1-8 hp against characters wearing non-bulky or no armor.
The lower jaws consist of two large, fused, chisel-shaped mandibles which move forward and backward independently of the upper jaws. After the first attack, the lower jaws are used once per round in an attempt to chop off a bite-sized piece of the prey; this piece is then swallowed whole. Attacks by the lower jaws do 1-6 hp damage, and are made at +3 due to the immobilization of the prey by the upper jaws.
In addition to the jaws, the Diopatra has four sets of hooked bristles under its first two pairs of fleshly lobes (called parapodia). These hooks are used to position the captured prey and are automatically considered to score a hit on the round after a successful attack is made by the upper jaws. No damage is done by this initial grasping.
To escape, a captured creature must either kill or severely damage the worm (reducing it below 50% hit points), or break free of the pincers and hooked bristles simultaneously. The pincers are AC 1 and have 4 hp, although blunt weapons may strike at the pincers at +2 to hit; reducing the pincers to zero hit points destroys them, though this does not reduce the worm’s normal hit points. A strength check on 1d20 will allow a PC to pull free of the hooks, which do 0-2 (1d3 -1) hp damage in the process. Pulling free of the pincers requires a bend bars/lift gates strength roll, which may be made once per round and causes 1-6 hp damage if successful. Pulling free of both pincers and hooks may be done in the same round if no other actions are taken.
The Diopatra lives in vertical tubes in soft sand, generally in shallow water or lower tidal flats. While feeding, it lurks near the top of its tube, using its long antennae to sense for vibrations and to “smell” chemicals emitted by possible food. The worm can distinguish the presence or absence of light, but is otherwise essentially blind.
The Diopatra eats anything (plant or animal, living or dead) that doesn.t appear too big and menacing. These worms lunge forward from their tube at a distance equal to one-third of their length to capture prey. The Diopatra are generally found in colonies rather than in isolation, with tubes spaced far enough apart so that the larger worms can.t have the smaller for lunch. Consequently, it is possible for a character to be attacked by two worms simultaneously if he is midway between two tubes.
The jaws of the Diopatra are hardened by thick deposits of aragonite (mother-ofpearl) and are of some value to knowledgeable jewelers. The upper jaws generally bring 5-10 gp per lb. depending upon their quality, with the whole set weighing 5-8 lbs. The lower jaws are highly prized, and may bring as much as 15 gp per pound, weighing 3-6 lbs.
Originally appeared in Dragon Magazine #133 (1988).