Ecology of the Xorn
Delving deeper down
The most important piece of equipment to bring with you into the deep sections of this mine is the provided purse of gemstones. The mine comes rather close to the Underdark and is oft frequented by Xorn. A few gemstones in your pocket to feed them can be the difference between life and death, as well as between profit or loss for the mine, so never forget them!
Introduction
The Xorn are in many ways as to the Elemental Plane of Earth as an awakened pack of wolves would be to an Elven forest. Both can be terrifying to see, the latter for its historical perception and the former for its outwardly appearance; if a party gets past that hurdle, then both are pleasant conversationalists with interesting information about their lands that can be shared; and both can turn ravenous, violent, and absolutely deadly if encountered in the wrong situation or provoked. The difference being that a pack of starving wolves specifically want the flesh off an adventurer’s bones, while the Xorn wants something far closer and dearer to an the adventurers' heart; their gold.
Physiological Observations
Xorn are native to the Elemental Plane of Earth and this otherworldliness is readily apparent in their anatomy. They frequently have three arms, three legs, and three eyes spread across their barrel-like torso, capped off with a mouth on the top; though there are infrequent variations, the number of limbs and eyes always match up. They evolved to deal with their native plane and the burrowing that is their main form of movement; their mouth and arms are configured for three dimensional space where forward is the most important direction. Woe be to those caught in the path of a Xorn, mouth and three mighty claws all pointed at them.
Their hide is unnaturally strong, more resilient than plate armor, yet supple and smooth to cut away nearly all friction. As such, it is nearly impossible to slice through with even mighty blows sliding off the hide leaving almost no scratch. Arcane and other master smiths, especially the Duergar, value Xorn hide above nearly all others when searching for rare materials from which to create light and some medium armors.
Xorn are slow creatures, however, even in their favored habitat of burrowing. Their connection with the Elemental Plane of Earth allows them to travel through the depths of the rock and soil without disturbing the material as it passes; it becomes one with the earth and passes uninterrupted through it. On worked stone, however, they will leave tell-tale signs of their passing, though to the untrained eye they may appear as areas of natural erosion or the shifting of the earth.
Xorn eat precious metals and gems as their standard fare, unable to digest any organic material. This diet likely makes their hide as strong as it is, and makes them terrifying to those possessed of wealth. They can smell gold and other metal and stone wealth from quite a distance away, and can pinpoint its exact location once within a short distance. Magical attempts to breed Xorn with other species in order to create a hybrid creature with this ability to sniff out wealth yet without the appetite for inorganic material have been so far unsuccessful, but are a common pastime among insane and greedy wizards.
Social Observations
Xorn are usually solitary creatures who graze on the fields of growing precious stones and metals in their home of the Plane of Earth. As long as food is abundant, as is the case in the Plane of Earth, they are quite docile creatures unless provoked. They are very territorial, but most confrontations between Xorn over territory are quickly solved by sizing each other up; confrontations with non-Xorn can be much trickier. They will allow travelers to pass without notice, however, so long as their food sources are untouched.
Xorn are capable of speech and will often converse with those interested, sharing their knowledge of the lands in exchange for gold or other edible wealth. By most reports they are incredibly strange yet likable creatures. However, they rarely speak any language aside from that of the Plane of Earth, rendering all but the most erudite of scholars unable to communicate with a Xorn.
Unlike many elemental creatures, Xorn mate to reproduce, leading some to speculate that they might have originally been from the material plane, possibly even descended from rust monsters, and adapted over many timeless ages to the Plane of Earth. They are hermaphroditic most of their lives but take on a gender only during mating season; the younger Xorn who wander across territories typically become male, while the older Xorn with more territory to themselves become female so as to better provide for and rear the young. They quite fortunately mate while underground and passing through the earth, for the sight of them doing so would likely be too much for a mortal mind to bear. The female lays between 2-4 eggs in a nest deep underground and surrounded by precious stones and metals, the eggs themselves created from and adorned with the most precious and valuable of materials. The young are capable of hatching and fending for themselves upon birth, but the mother Xorn checks in on the eggs from time to time and takes a more protective role after the young hatch. The eggs, both the shells after hatching but especially unhatched and preserved, are often among the most valuable items in a Dao’s treasury due to their rarity, difficulty in obtaining, and pure opulence.
A Xorn which has unfortunately been removed from the Plane of Earth, be it by accident or the meddling of the more powerful (they would never leave intentionally), is a much more desperate creature. They travel deep within the earth, often through the Underdark or nearby particularly deep mines, searching for sustenance. Even the wealthiest mines rarely provide enough of a diet for a Xorn, and as such will seek out great concentrations of wealth in the forms of dungeon stashes, wealthy storehouses, and unsuspecting adventurers who carry all their wealth on their backs. It will try to trade for or beg for food as a first resort, but often due to communication problems and to most recoiling from the Xorn’s horrific appearance, it will quickly turn to intimidation and force to obtain its meal.
Behaviorial Observations
As long as they are well fed, Xorn are docile creatures, not immediately friendly but neither are they rude or cruel. They cannot be tamed, but they can be made to respect boundaries with a little bit of friendship and courtesy.
Xorn prefer to stay below ground, emerging only into deep dungeons and mines in the pursuit of food. It is exceptionally rare to see them above ground on the material plane, though they can more frequently be found on what constitutes ‘above ground’ in the Plane of Earth.
So long as they are not provoked or their food source taken, a Xorn will remain apathetic to others crossing its territory. If challenged, it will rear itself up and wave its arms, stomping in rhythm, to attempt to scare the intruder away; this is how two Xorn would size each other up to determine a territorial dispute. If this is ineffective, the Xorn may attack, especially if it feels bigger, using its burrowing to ambush targets with a barrage of quick attacks before disappearing into the earth again. It will use that burrowing to escape as well if the battle goes poorly.
Inter-Species Observations
Xorn infrequently interact with other species, or even with other Xorn, because of their preference to live as one with the earth, swimming through the stone and dirt as a fish through water. Their high tremorsense means that they are capable of avoiding dangerous tunneling monsters that share space with them, like Purple Worms. Few others truly venture into their realms.
Those that do include the Dao and Duergar, neither of which much care for Xorn. Dao often find ways to establish boundaries between Xorn and their treasuries, usually through intimidation more so than violence. Duergar, however, prefer violence as Xorn hides are valuable components to masterwork armor.
A wizard or other adventurer capable of speaking in the Xorn’s native tongue should find a creature willing to trade information for wealth. They are not particularly talkative, and any discussion with one should be a slightly surreal and mind-bending experience, but repeated courteous contact could produce something like a friendship. A starving Xorn stuck on the material plane is very unlikely to form these sorts of bonds, but helping it return to the Plane of Earth would earn its eternal gratitude.
DM's Toolkit
A Xorn is an excellent enemy for hoarder PCs, for nothing strikes more fear into that style of player than watching their probably ill-begotten wealth devoured and made irrecoverable. They can appear on a deep dungeon dive or in the Underdark, but could be used sparingly in other situations.
They have a very high AC, formidable HP, and a resistance to non-magical slashing and piercing that will confound and imperil low-magic parties. In parties with mages, use their burrowing speed to disappear into the ground, taking the opportunity attacks as they vanish and trusting their AC and high HP to hold out, and appear underneath an unsuspecting PC with multiple ambush attacks. Used like this, they should be far more dangerous than any other CR 5 monster and remain a dangerous enemy for some time. Even once badly outclassed by PCs, a Xorn can still use its burrowing and camouflage to threaten the gold stores of a party that doesn't invest their winnings, pushing a party to become more invested in other aspects of the world.
Capitalize on the contradictory nature of the Xorn. They are terrifying to behold and should instantly strike fear into those who do not know of them just from their description. Yet they are simply hungry and would rather find their meal peacefully, creating some moral tension.
On a meta-level, your players might not know of Xorn, so could truly surprise them. As a kinda-elemental, the PC knowledge check concerning them should be Arcana, but because of their rarity it should be a difficult check to make.
