Mortiss

A mortiss was a type of space worm that consumed wood and minerals present in small asteroids and the hulls of spelljammers. Despite being more closely related to species of coral, they were usually referred to as the "termites of wildspace".

Description
Mortiss were round worms with no eyes who sensed their environment through vibrations. They had a ring of feather-covered tentacles around their heads, which consisted of two pairs of jaws and a poisonous stinger. Hatchlings had a length of about 2 in (5.1 cm) and grew up to 6 ft (1.80 m).

The worms could not survive in a large body's atmosphere. They lived exclusively on small bodies and ships. If brought into a planet's or a large moon's atmosphere, mortiss died out within one month.

Behavior
In the presence of light, mortiss had the ability to magically convert wood and minerals into a type of clay that they used to shape their burrows. The early stage of an infestation, which manifested as small holes on the most brightly lit side of the hull, was difficult to detect, but in later stages they sculpted stony tubes that protruded outwards from the hull.

If left unchecked, a mortiss infestation effectively destroyed a spelljammer within one year, completely encasing it in the stony substance. For that reason, some scholars speculated that certain small asteroids and even small moons might have been the result of previous infestations, and could still contain structures hidden underneath the surface.

They were a hermaphroditic species. Individuals mutually fertilized each other's eggs, which resembled geodes, and then deposited them on a speljammer's hull that had come in contact with another infested body, such as an asteroid, infested cargo, or another spelljammer. In some cases, eggs that were adrift in space might also become attached to a passing ship's hull. The eggs hatched within one week of laying. The young started digging their burrows within three to four weeks.

Combat
Mortiss were vulnerable to fire and remove disease spells. If their burrows were attacked, they responded by stinging their attackers. The poison present in the stinger had a hallucinatory effect that lasted for several hours and was increasingly more difficult to overcome with each subsequent sting. They could also attach themselves to other creatures, slowly draining them.

Ecology
Although mortiss did not usually seek out other types of life, it was common for creatures to associate with them in a symbiotic fashion, since mortiss renewed the air envelope of celestial bodies. Creatures such as elmarins, kindori, krajens, and scavvers were known to establish lairs among mortiss colonies.

Mortiss meat was considered a savory delicacy. Crates were typically stored in Stardock for its githyanki inhabitants in the late 15 century DR.

Appearances

 * Waterdeep: Dungeon of the Mad Mage (mentioned only)