Rare and prized creatures, gem moths glitter with jewel-encrusted chitin, their wings emblazoned with whorls of precious stones in bizarre and beautiful patterns. Their bodies reflect moonlight and send out colorful beams of light into the darkness, signaling hunters for miles around to their presence. No one who sees a gem moth will ever forget it, and those who can capture them are rewarded handsomely for their efforts
Born from eggs like any moth, their caterpillars instinctively seek out rock and stone, favoring those with high mineral deposits. Some aquatic larvae swim into silty water, filtering for the rich sediment found within. Terrestrial gem moth larvae secrete a powerful acid that is capable of melting even the hardest rock, which they then consume using a thick, flexible proboscis. These caterpillars are often dull gray or black in color to help them blend in with their rocky habitat, and have hook-like barbs in their feet that allow them to cling to sheer rock faces and cave ceilings.
Gem moth caterpillars require no organic food to survive, as their internal biology is able to extract energy as a byproduct of their diet. Inside these larvae, the rock and mineral ingested is subjected to an intense reaction that breaks down and reconfigures its molecular structure, resulting in gemstones that are created over the course of the caterpillar’s year-long existence. Assuming that these larvae can obtain enough stone to fulfill their dietary needs, they will live out this period gorging themselves and molting repeatedly. There is no upper limit on a gem moth caterpillar’s size, with some of the largest reaching sixty centimeters.
Due to their esoteric biology, gem moth caterpillars face few natural predators, as they contain little in the way of protein. For the few hardy species that also exist primarily on inorganic material, they make for quite the meal, leading to them developing a variety of defenses. Their acid spittle can also be shunted through their exoskeleton, using body contractions and small tube-like protrusions to jet the acid out at high pressure over great distances. Some caterpillars have the ability to lock their body segments in place and become as hard as the stone they eat. Others have developed spines and spikes, while others have brightly colored bodies that warn predators of the powerful acid contained within them. A singular offshoot has even developed a very novel self-defense strategy: keeping their latest molting around like a suit of armor. When threatened, they expand rapidly and the molt shell explodes at high speeds like a bomb, leaving the caterpillar unharmed and ready to dash for safety.
After they have completed roughly a year of life in their larval stage, the gem moth caterpillars seek crevices where they can pupate, extruding a cocoon around themselves composed of pure gemstone. The gemstone in question is unique to the larva’s species, but they are often irregularly shaped like a raw stone. If held up to light, one can witness the process of pupation happening within. These gemstone cocoons can vary in size from three centimeters up to a record seventy centimeters. Once the moth has completed its transformation it easily cracks the stone open through an unknown process. During this period the stone becomes soft and pliable, only hardening again once the moth has exited it.
In their adult imago forms, the gem moths come in a striking variety of gemstone coverings. The most common are amethyst, citrine, emerald, ruby, sapphire, tanzanite and tourmaline. But all gemstones have gem moth equivalents, with diamond, opal, pearl and turquoise being the most prized. There is little consistency in body size with gem moths, even within the same species, as mass is dependent on the amount of stone they were able to consume as larvae, leading to all sizes of these magnificent creatures taking flight as soon as they are able.
As adults, gem moths have exceptionally long lifespans, living for decades or even centuries depending on their species. Their bodies, encrusted with gemstone and patterned into busy and beautiful designs, are exceptionally hard to damage and their natural agility in the air allows them to escape most forms of attack. They have few natural predators, leaving sentient beings as their primary hunters. No longer hungry for stone, gem moths consume a standard diet of plant nectar and spoiled fruit. The exception to this are gemstones of their type, which they seek out and consume with single-minded hunger. This is the only way for gem moths to increase in size as the gemstone mass is added to their own. Due to the rarity of gemstones, this does not lead to many large gem moths in general.
Due to their long lives and exceptional longevity, there is not much pressure on gem moths to reproduce rapidly. Every decade, during a conjunction of the moon and planets, there is a mating night for gem moths. They fly high into the night sky, catching the unique light of this night and forming a glittering swarm that looks to many like an aurora. After their mating is done, they scatter once more, with eggs being deposited in dark, secluded places. Parents do not remain to watch over their spawn, trusting them to get by on their own.
When natural death finally comes a gem moth, they prefer to alight on the ground itself, venturing out during the day as they so rarely do, seeking a sunny spot to breathe their last. After expiring, their organic components rapidly decay, leaving a pile of gemstones in this seemingly random spot. Many a fortune was built on the corpse of a gem moth found in a sunbeam on a pleasant day outside.
Gem moths avoid civilized areas out of more than a rudimentary fear of sapients. Artificial light plays hell with their navigation, causing them to become clumsy and uncoordinated. They can handle the light of a single fire or torch, but if they find themselves surrounded by several sources of artificial light they become frantic as their connection to the moon and stars is confused. In this state they fly into surfaces and can fall to the ground.
For all their defenses and nimbleness, gem moths are still brought down by hunters seeking to rip the gemstones from their bodies. There is a small but voracious industry of gem moth hunters that seek out the insects and employ various means to capture, kill and then strip them of their valuable carapaces. Such work takes a high degree of skill, a willingness to venture far from civilization, and a great deal of patience waiting for these elusive creatures to emerge from their hiding spots. To say nothing of the requirement to hunt at night, when other predatory creatures are far more likely to also be on the hunt.
Besides hunters, there are others who make use of gem moths in their own way. Foragers crawl deep into caves in search of their gemstone cocoons, which can be subjected to an alchemical process that breaks it down into jewelsilk, highly prized and valuable fabric material. Mages value gem moths for their ability to store magic, capturing them for use as ways to extend their power further. Crafters will pay handsomely for the fresh wings of a gem moth, as they can be treated with heat and pressure to preserve them as very sturdy surfaces for use as art pieces or armor.
Cultivation of the gem moth is difficult, as their eggs are nearly impossible to find and they only mate once a decade in a ritual that they will not perform if held in captivity. This has not stopped a rare few breeders from managing to build small domestication operations that largely rely on hunters bringing in new live specimens. Using arcane marking, these moth ranchers are able to keep track of their stock after the mating night, and can observe them closely enough to cultivate their eggs. This process is highly labor-intensive, and the competition is fierce. Assassinations, theft and sabotage are common among these groups, keeping the supply of steady jewelsilk low.
Gem Moth Caterpillar
Defense: See the Caterpillar Defenses table.
Gem Moth
Attack: See the Gem Moth Attack table.
Species: See the Species table.
Caterpillar Defenses
Gem Moth Attack
Species
Roll d66
Other Types
Great Gem Moth: Mutations have led to some gem moth larvae consuming truly incredible amounts of raw material, growing to immense sizes as a result. Anywhere from a meter to three meters in length, these cocoons disgorge gem moths of incredible size. These massive insects behave no differently from their normal brethren, and their mutation cannot be reliably passed on. Sightings of these creatures have mobilized cities, and their appearances have coincided with wars between vain states wishing to possess their precious bodies. The remnants of their cocoons alone have upended markets and crashed local economies.
Attack: See the Gem Moth Attack table. Roll twice.
Species: See the Species table
Prismatis Majorae: Another rare mutation, these gem moths do not produce a single kind of gemstone, but several. As a result, their bodies are a tapestry of brilliant colors woven together into a unique pattern that dazzles the eye. They are also gifted with a reservoir of magical power which they deploy with a rudimentary intellect that operates solely in self-defense. Even more prized than normal gem moths, the prismatis majorae are sought after by collectors who wish to display their preserved bodies in full, and any damage to their carapace ruins their value to these highly-discerning clients. Luckily for most gem moth hunters, that still leaves them with a pile of valuable gemstones for their less picky buyers.
Attack: See the Gem Moth Attack table.
Species: See the Species table. Roll 5 times.
Spells: Magic Missile (2), Shield (2), Invisibility (1), Mirror Image (1), Lightning Bolt (1)
Bloodmoth: An uncommon subspecies, these gem moths have developed a predatory behavior and an appetite for blood. This rich diet comes with another helpful adaptation: the ability to convert blood into more gemstone, adding to their mass. With the ability to grow larger, bloodmoths can predate upon bigger creatures, fueling even more growth. This leads to large and bloated bodies, distended abdomens swollen with gemstone shot through with streaks of stored blood. As valuable as any gem moth, the stones harvested from this species hold even more value to blood mages and less scrupulous alchemists, as their blood-filled gems can be used for esoteric dark rituals and concoctions. Hunters should beware, bloodmoths are every bit as nimble and hardy as their cousins, but also have razor-sharp talons and a bladed proboscis capable of punching through armor and draining a human dry in seconds.
Blood drain: Upon a successful attack attaches to the victim and drains their blood: 1d3 automatic damage per round.
Detaching: If the bloodmoth or victim dies.
Attack: See the Gem Moth Attack table.
Species: See the Species table
Gem Moth Lord: By far the rarest gem moth variety, these creatures are not a species or a mutation. Instead, they are the result of a gem moth caterpillar that feeds on stone that resonates with magical energy. This etheric suffusion results in a very different kind of reaction inside the caterpillar, leading to their metamorphosis into a gem moth lord. Taking on a humanoid form, tall and lithe with four arms and an extra set of wings, the lord is imbued with an alien intellect to match even the smartest among the sapients. Gifted with an innate talent at magic, gem moth lords quickly become fearsome creatures that evade detection and stay far away from civilization. Gem moths are drawn to lords, who can communicate with them and relay instructions that are far more complex than insects should normally understand. Highly protective of their subjects, gem moth lords pursue a vendetta against hunters. During the mating night, the lords, who are sterile themselves, take to the sky and protect the mating moths against hunters and predators.
Attack: See the Gem Moth Attack table. Roll twice.
Species: See the Species table
Spells: 1st Level (4), 2nd Level (4), 3rd Level (4), 4th Level (3), 5th Level (2)
Rumors and Talk
Gem moths can be confused by surrounding them with torches.
Some gem moth caterpillars will eat chicken eggs.*
Ground up gem moth carapace is a potent narcotic.*
The alchemical formula that creates jewelsilk is a jealously guarded trade secret.
Fried gem moth caterpillars are a delicacy.*
You should lock your gems inside a lead-lined box, gem moths can’t smell them inside.
People who get hypnotized by a gem moth see them in their dreams forever.
A gem moth wing is the sharpest blade in existence.*
Adventures
A gem moth has been sighted near the small town Coswall, causing a rush of adventurers and hunters. Overnight the village becomes a boomtown as everyone tries to cash in on the craze. While the hunt is on, a masked killer moves among the newcomers, picking them off in the dead of night.
The remains of a gem moth are found just off a path through a secluded valley. The two families who live there have gone to war over it, hiring mercenaries to help out with promises of jewels. Meanwhile, two scions from the opposing sides plot to steal the gems and elope.
The wizard Velshon the Wild has stumbled upon the secret lair of a gem moth lord deep in the mountains. He hires the party to go in, slay the lord and any gem moths as they can, promising them half of the gems as their reward. When they confront the lord, calling itself Glass-Eye, it implores them to leave it in peace and kill Velshon instead, offering to help them.
A circle of druids has made gem moth protection their mission and their philosophy is spreading. These druids and their followers stalk and battle gem moth hunters. A coalition of merchants have put together a reward for anyone who finds and kills the druid leadership.
Encounters
1d8+2 bandits are fighting 1d6+1 gnolls for the corpse of a gem moth. Allying with either side will lead to them agreeing to split the gems. Negotiating a peace will lead to each side taking a third.
1 dragon (of a type appropriate to the terrain) attempting to capture a great gem moth. Due to its preoccupation, it can easily be surprised.
The desiccated corpses of 3 oxen and 1 human. 1 bloodmoth rests nearby, ready to attack and drain anyone passing by.
A rare meeting between 2 gem moths of different species. An invisible stalker waits nearby to snatch both of them for its wizard master.
3d4 gem moth hunters stand entranced in a clearing, staring up at the moon. A prismatis majorae has left them hypnotized and is fleeing the scene.
A pair of foragers with a gem moth cocoon are hiding from 2d6+2 nearby hobgoblins who are searching for them.
Items
Jewelsilk Garment: Anything made from this glittering thread, colored according to the species of gem moth cocoon it was taken from, is considered extremely beautiful and highly valued. Wearers get +2 to the reaction roll and may, once per adventure, re-roll a failed Charisma check.
Glitterblade: A metal slashing or piercing weapon treated with dust from a gem moth that gives the surface a jewel-encrusted appearance. Counts as a magical weapon.
Mothspawn Acid: Bottled and highly potent corrosive liquid derived from gem moth caterpillars. Inflicts 2d6 damage per round until scraped off, but is most effective against stone. A bottle can eat through three meters of stone with a two-meter diameter.
Razordust: A bag of ground up jewels and carapace harvested from a gem moth. When thrown or blown it fills a 10’ space in front of the user. Those caught in this area must save vs. breath or take 2d6 damage. It also occludes the area, providing cover (-1) to those within and on either side from missile attacks.
Gemfinder Rods: A pair of gem moth antennae used in conjunction work like dowsing rods, leading the holder to any gems within 200’.
Nightsight Lenses: Glasses with thinly-cut gems from a gem moth. When worn, they allow the user to see perfectly in darkness. Additionally, they can see any gems up to 10’ inside a stone surface.
Glintrope: Woven from strands of jewelsilk, this beautiful cord is completely indestructible and can bear an unknown amount of weight. No one has ever tested its true capacity. 100’.
Mothlight: Taken from the relatively common rose quartz gem moth, this crystal can provide warm reddish light equivalent to a torch for up to 8 hours. It must then be left in a fire for an hour to recharge. Activates when shaken. Creatures that sleep in the light of this crystal regain an extra 1hp.
Mesmer Disc: A piece of gem moth wing, thinly preserved gemstone with an intricate pattern left upon it. Creatures that see the disc must save vs. wands or be stunned for 1 round. After performing this save, the creature cannot be affected again until it performs a rest.
Rockfeast: An alchemical solution derived from the digestive juices of the gem moth caterpillar. Allows one who ingests it to eat rocks for 1 week. A pound of rock or stone acts like a ration for the user.
