Giant Tube Worm

The common giant tube worm stands about 6 feet tall and 2 feet across inside a tough, dark yellow casing. Its pale yellow body ends in a flowery crown that unfurls when it feeds. Carnivorous tube worms, or blood worms, look nearly the same but lack the plumes; instead their heads open into wide mouths full of vicious teeth. Thankfully, they are rarer.

The common worm cannot attack at all. Its soft body is only AC 7, so it depends on its AC 2 tube. Sensing pressure from sound and movement gives it +2 to avoid surprise, and at any threat, which is nearly always, it pulls inside and seals the top with an AC 2 valve.

Blood worms hide among their mild cousins and are 90% indistinguishable from them. They wait for a meal to come close and then strike with speed and fury (+2 to surprise), their flexible bodies reaching 3 feet in any direction from the tube's mouth. Beyond the teeth, their saliva carries a mild burning, itching venom: a victim who fails a save vs. poison (made at +2) loses 2 Dexterity for 1d6 turns. Not brave, they retreat into their tubes after losing more than half their hit points.

Both kinds live only around hydrothermal vents, and hotter, richer water means more worms. Both reproduce sexually, the female releasing several thousand young from a genital valve near her head. Neither gathers treasure, though now and then something turns up at the base of a blood worm.

Common tube worms host chemosynthetic bacteria in their guts that turn mineral particles into food. Many creatures eat them and lair in their emptied tubes, though outsiders to the vents find the sulfur-heavy meat inedible. Blood worms eat nearly anything they can seize, and deep-sea octopi consider them a real pest.