[Cosmosdex] The Universal Encyclopedia



Pack Slugs

“This bad boy can fit so much acid in it.” — Gastimud Salesman

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  • Strength-4
  • Intelligence-1
  • Charisma-1
  • Endurance-5
  • Agility-3
  • Luck-8

Danger Level: Low
Likes: Gastimuds, Moistness, Warmth
Dislikes: Loud Noises, Metallic Surfaces, Salt

Attack Method: Produce a great deal of acid, in hopes of immobilizing a foe or rendering them prone, before dripping acid in their mouth.

Environment: Underground Caverns, Mountains
Lifespan: 8 years
Size: 2 ft tall, 4 ft long
Diet: Certain geological minerals, particularly sulfides and sulfates

Bodytype: Serpentine
Type: Elementbound Mollusk
Rarity: Uncommon

Original Creator: ten11

Physical Description

Gastimuds resemble large slugs roughly two feet tall, with the front half of their body narrowing to a small, wet appendage. This appendage constantly secretes a small amount of acidic liquid, which quickly loses potency once separated from the source. Towards the back of a gastimud, their skin turns hard and rough, taking on a texture reminiscent of whatever minerals make up the creature's diet. This section of their body is safe to touch, and contains the organs that are most biologically important.

Gastimuds are almost entirely blind, and perceive the world through smell and touch instead, which allows them to distinguish between different types of rocks.


Gastimuds dwell in underground caves and tunnels, usually in small packs of around a dozen creatures. These groups have leisurely lifestyles, moving very little as they graze on their surroundings. The acid they produce softens and dissolves rock, allowing it to be absorbed and then slowly digested by the gastimud's stomach, but each individual only consumes a small amount of rock each day. The majority of what they eat is integrated into the surface of their body, where it remains until the gastimud grows too large and sheds its skin. While their acid is effective against most rocks, gastimuds are actually somewhat picky in their diet, and will move on from an area if the minerals present aren't to their liking.

When threatened, the survival of the group is valued over the survival of an individual, and one or two gastimuds will stay behind while the rest attempt to escape. These individuals will begin producing far more acid to fight off the predator, to the point that they will suffer internal damage even if they survive. Gastimuds are placid creatures by nature, however, and will not react strongly to the presence of unknown creatures until they are attacked.

Due to their limited rate of consumption, gastimuds are unlikely to destabilise an underground structure, however this does still happen occasionally. If buried, a gastimud can slowly dig themselves out through use of their acid, but the same cannot be said for other species in the area. This has led to the fauna being considered a pest in most underground settlements or mining colonies, with populations being wiped out whenever they're found. Some planets have managed to domesticate the fauna however, milking them for their acid or training them to aid in mining efforts.


Sleigh gastimud: This subspecies has been created in captivity through selective breeding to be much larger than typical gastimuds, as well as having greater acid production. This enables the creatures to be used as pack beasts on planets where overland travel isn't possible, as they can simply dissolve a tunnel through the underground mantle between any two places. With a team of ten well-fed sleigh gastimuds, it is possible to traverse through up to fifteen miles of solid rock in a single day, though the passages they leave behind will often be unstable and collapse shortly after passing through.


Organic acid: Gastimuds are capable of producing a special organic acid, which causes most stone to liquefy upon contact, creating a slurry of mud and acid. This slurry quickly resolidifies if no new acid is applied, leaving odd rock formations behind. Metal is almost entirely unaffected by this acid, and living creatures will experience a mild stinging sensation, but suffer no serious damage unless exposure extends for several minutes. The acid is, however, poisonous, and should not be consumed.


• Gastimuds have breeding seasons every few years, when different packs seek each other out for the purposes of reproduction. Following this, the adult and newly born gastimuds will split into several packs, usually mixing up the original groups, and go their separate ways.

• If a gastimud is separated from the rest of its pack, or grows up without one, they will tend to grow less than other gastimuds, eating less rock and producing less acid. Such a separated individual will be more fearful of predators and strangers, and may be reluctant to join a pack even if given the opportunity. This still applies in domesticated breeds, which are usually raised and sold in packs to prevent this affliction.

• Attempts have been made to breed gastimuds suitable for pet-raising, with smaller acid glands and cuter 'heads'. However, the need for their own company has proven impossible to remove so far, and most people aren't interested in handling multiple slugs capable of damaging the neighborhood's roads and sidewalks at a single time.

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