Cave fisher

A cave fisher is a lobster-like monster which inhabits subterranean locations and ambushes its prey using a sticky filament similar to a strand of spider silk.

Description
Cave fishers grow to about seven feet (2.1 meters) long and have a hard, chitinous shell arranged in overlapping plates for an exoskeleton. It has eight legs and two forelimbs which end in large pincers. Living underground, the cave fisher is a sightless creature which used multiple auditory sensor organs to detect prey. These organs are located on the head and can be mistaken for multiple eyes. The creature has a large proboscis from which it shoots a long (up to 60 feet or 18 meters) sticky filament.

Behavior
The cave fisher hides on ledges above passageways and hunts by emitting a long strand of sticky filament, either dangling it to catch passing creatures such as bats, or shooting it at a creature as it wanders by. They can also secrete their adhesive onto their feet and anchor themselves to a ledge, wall, or ceiling once they found a good hunting spot. To release themselves, they secreted a substance from their proboscis that contained their blood that dissolves the adhesive.

Cave fishers will attack any creature up to man-sized, but are intelligent enough to avoid large groups, preferring to pick off scouts, loners, and stragglers. Normally, cave fishers work lone in a area within 300 feet (91 meters) of its lair, but sometimes they could be found in small groups of less than five, and these pods are known to coordinate ambushes of small parties. This cooperation usually ended when there was food to be fought over. Extra food, alive or dead, is wrapped in filament and stuck to a surface in their lair for later consumption.

Cave fishers have no use for clothing, armor, or weapons, so their lair is usually strewn with the possessions of former victims.

Combat
On a successful attack, the victim is stuck to the cave fisher's filament and was slowly drawn up to the cave fisher's level where it attacked with the two front pincers. Cave fishers can reel in victims weighing up to 200 or possibly 400 lbs (91 to 182 kg). Their filament is very difficult to cut, perhaps even requiring a magically enhanced blade, and any failure to do so results in the blade being stuck fast.

Cave fishers have flammable blood and therefore are very adverse to fire. Casting silence on a cave fisher made it freeze in place as it listened intently, attacking only (and much less effectively) if it was attacked first.

The filament is almost invisible in a dark cave, even at close range. A detect snares and pits spell would reveal them, however.

Ecology
A vave fisher's diet is primarily bats,   and they never attack anything that they detected is bigger than themselves, but they're always cautiously looking for larger prey they could surprise, like a lone goblin, orc, or foolish adventurer.

Cave fishers can live over one hundred years and females mated about every twenty years. They send out a ultrasonic keening above the hearing range of humans and demihumans, which attracts all males within miles of her lair. The first male to approach the female is allowed to mate with her and then become her victim. Any latecomers are forcefully rejected. After a three-day gestation period, the female lays a clutch of five to nine fertilized eggs in the body of the male and then departed to establish a new lair away from her previous nest. Within a month, the eggs hatch, the young lived off the carcass until it was depleted, and then they scattered to establish their own lairs. It takes a little over two tendays for the young to reach half their adult size, and then their growth slowed, reaching full size in a year.

Almost every part of a cave fisher is usable after the creature had been killed. The meat is edible and tasted similar to crab sauteed in stout wine. Its blood is used for concocting several dwarven spirits, although some hearty dwarves drink the alcoholic blood straight. Extruded cave fisher filaments can be harvested and treated to dilute the adhesive and then woven into ropes that are incredibly strong for being so thin. The diluted adhesive can even be applied to gloves and boots to improve their grip when climbing. The chitinous shell is very tough and could be used to make armor, tools, and even jewelry.

Cave fisher eggs that were a tenday old or less are highly valued for their alcoholic content plus psychedelic properties. A sip from one of these eggs can cause an average human to become quickly intoxicated for hours while experiencing hallucinations. Consuming the full contents of one of these potent eggs is usually fatal. Fresh cave fisher eggs sell for 50 to 100 gp in most large cities.