Dragons are sentient beings which are considered the most powerful individuals on Mersia. Dragons are characterized by their inherent ability to use shapeshifting magic, their ability to ignore the laws of thermodynamics, their extreme longevity, and their ability to speak.

Dragons are eusocial vertebrates which have six limbs. Two forelimbs which terminate in hands, two rear limbs which terminate in feet, and two wings. Dragons have no known maximum lifespan, they simply get larger with age.

Dragons have no maximum size, but their growth rate does slow down at around 250 years. The growth rate slows down again at around 5000 years, but it does not reach zero. The oldest dragons, those that exceed 20,000 years, are more than twice the size of those that are 5000 years old. The oldest dragons in history tend to be around 50,000 years old, and may be as much as 50% larger than dragons of 20,000 years. Dragons do not experience senescence, and typically only die if killed in battle, or otherwise when they no longer want to live.

Dragons have a complicated system of reproduction which enables a dragon to sexually reproduce with sapes in order to produce a caste of largely subservient hybrids in a variety of biological castes, determined by the rough percentage of draconic ancestry inherited by each. The existence of these castes and the nature by which they are born is why dragons are classified as eusocial. In addition, dragons can freely change their biological sex at will, so they can either father or mother offspring depending on specific need, as well as partner with whichever individual they please. Some dragons prefer to present as masculine or feminine, but all dragons inherently have the ability to switch at will.

In addition to the same complement of vital organs as a sape, including the olum which contains the dragon's potentia, dragons have an additional organ in their throat called a lairn, which is the organ allowing a dragon to utilize their breath ability. The exact structure and function of the lairn may differ drastically depending on the tribe the dragon belongs to.

Dragons are extraordinarily physically durable, and in addition to this can survive wounds which would easily be fatal to any other creature (including the removal of the heart or destruction of the head). For this reason, when a dragon is felled in battle, the killer (usually another dragon) will methodically dismember the dragon and scatter and hide their bones to keep them from coming back. If the bones are reassembled within a century of the dragon being killed, it may come back to life (although the process may take decades, and the reforming dragon is largely defenseless during this time).

A dragon's teeth and bones are harder than any metal and are nearly impossible to destroy for the first several centuries after a dragon is killed. It is only after the dragon's life force entirely dissipates that its bones can be damaged.

A dragon's lifecycle is long and complex.

Mentally and emotionally, dragons mature at a similar rate to sapes, with dragons having reached adult levels of critical thinking, emotional maturity, and reasoning by age 25. Physically, however, dragons take far longer than any other being to fully develop.

A dragon's basic education is generally completed by age 40, at which point most dragons are 10 feet long (not counting the tail) and weigh around 600 kg. They are typically raised by a demiwyrm or alwyvern of the village overseen by their biological parent.

Dragons reach sexual maturity at around 200 years, at which point most dragons are 16 feet long and weigh around 1400 kg. At this time in a dragon's life, they will leave the territory of their parent, bringing with them a small detachment of residents of that territory who swear loyalty to that dragon.

As a dragon grows older, their primary focus is on either building a new settlement with their followers, on finding a village with no dragon ruling it, or on taking over the territory of another dragon. Once the village is self-sufficient, the dragon will typically make a journey to the south to find a sape (or multiple sapes, but typically younger dragons will only have one) to take back to Feyndraig as a breeding partner.

As the settlement grows, the dragon will spend less time directly managing the affairs of their territory, and delegate more of the routine and mundane responsibilities to their followers, typically an alwyvern or draigfolk, though there are rarely young dragons with speaker or demiwyrm followers. The dragon will instead focus more on warfare with neighboring settlements for the purposes of either gaining territory or new followers.

As a dragon's territory expands to cover multiple villages, their focus will shift from open conflict to diplomacy, to ensure their territory has a stable future. This is necessary for the dragon to ensure they have enough food to continue growing stronger. A dragon's future strength over their entire life is strongly determined by how much they can eat in their first 5,000 years. A territory of five to ten villages is typically enough to fully meet the needs of a growing dragon, but some dragons are more ambitious and attempt to manage a larger territory than they strictly need. This is a riskier strategy, but the strongest dragons are those for whom the risk paid off.

As a dragon nears 5,000, it becomes increasingly likely that the dragon will seek out multiple breeding partners at once (most often unrelated demiwyrms, speakers, draigfolk, and sapes) in order to have as many offspring as possible, and to improve genetic diversity within their territory. Earlier in life, dragons attach sentimental and romantic significance to each breeding partner, but as dragons inevitably outlive their partners, they gradually find each new partner to be a less and less significant part of their life. 5,000 is considered the threshold of adulthood among dragons. At this point in a dragon's life, they expand their territory less aggressively and their focus shifts to maintaining the kingdom they have built.

Dragons who reach the age of 20,000 are considered to be elder dragons, and at this point in their lives, they will stop reproducing with sapes or other draconic folk if they have not ceased already, and most will either spend the remainder of their lives alone or otherwise seek a romantic relationship with a dragon or fae. It is from these relationships between dragons, typically late in both dragons' lives, that new dragons are born. Younger dragons will not typically have offspring, because of their own long lifespans, and because when the dragon is of age they will often try to compete with their parents for renown and territory.

As dragons approach their 50,000th year, they gradually defend their territory with less and less vigor, as less and less changes from year to year. The faces of the villages they govern blur together, and they cease to recognize any individuals. Their memories become a larger and larger portion of their reality until they only have their memories. They prefer to spend their time recounting their younger days to any who will listen, but as the vast majority of a dragon's close associates are much shorter-lived, the dragon will feel increasingly alone regardless of how many people the dragon is surrounded by. It is not senescence that ends a dragon's life, but apathy. Younger and more vigorous dragons will come along again and again to challenge the dragon's reign, and eventually one will succeed.

In rare cases, specifically cases where a dragon intentionally erases or archives their memories on a regular basis to avoid the days blurring together, dragons can potentially live for far longer. The oldest dragon on record (apart from the mind dragons who are as old as the planet), Kehmevendial, was over 250,000 years old.

Dragons are unique among living beings for their ability to self-resurrect so long as at least 85% of their bones are gathered into one place and then loosely assembled. In nearly all cases of resurrection, it is done within a century of the dragon's death, and when possible, done within the dragon's former lair, where the dragon's lair angel may guide the resurrection process.

If a dragon does not wish to resurrect, then it won't. Its soul will gradually return to the soil and the leylines. But dragons who were killed through betrayal or trickery are less likely to accept their deaths, and their resurrection becomes far more likely, especially if that dragon has loyal followers surviving.

An incarnate dragon's soul is immortal and retains some feelings and opinions across bodies. Each subclass of dragon has twenty dragons within their own cyclical reincarnation order, with the oldest of each tribe reincarnating as the youngest within the wheel. A dragon's surname is the name of the wheel they belong to. For example, the Ansel wheel of the poison tribe is the current wheel of incarnation for that tribe. There is no synchronicity between different tribes. A cycle is said to be “perfect” when all incarnates in that wheel died and were reborn in the same order as the previous wheel. A cycle is said to be “imperfect” when its incarnates died in a different order than in the previous wheel, and consequently, with the order of its incarnates different from the previous wheel.

A dragon's given name is the name held by their former incarnation. For example, Arcturus Ansel is the current incarnate of Arcturus Onna. This means that Arcturus Ansel holds many of the same feelings and opinions as his former incarnate, Arcturus Onna. They are, indeed, the same soul with a new body and mind.

An outcycler is a dragon who is not an incarnate, and therefore a 'new soul'. Alsyrna Bolnayn is an example of an Outcycler from the Explosion Tribe. The vast majority of dragons are outcyclers.

A lair is the primary residence of the dragon. It is the place where a dragon will sleep most often. The characteristic which differentiates a lair from any other residence is that a dragon's lair will develop a type of fae called a latebrangel if it did not already have one.

The lair is typically heavily warded both magically and physically and may contain a sprawling (or even continually expanding) layout, armed guards, a hoard, servants, mates, a space to conduct diplomacy, and a trading hall.

A latebrangel is a similar sort of being to a resangel, with the distinction that only a dragon can create a latebrangel. This latebrangel will imbue its dwelling with wards and amenities intended to facilitate the comfort of the dragon and the security of its holdings. It is a symbiotic relationship between the dragon and the latebrangel. The latebrangel feeds on the potentia of the dragon, and the dragon is protected and cared for by the latebrangel. The latebrangel will additionally aid the guards, expand the physical defenses of the lair, assist in conducting lair business such as diplomatic meetings and trade, and protect the dragon's mates and servants. A latebrangel is a monolitic consciousness but will usually split itself into multiple subforms to enable it to complete all of its functions.

However, a latebrangel's loyalty only extends as long as the dragon and their forces are capable of defending the lair from intruders. If the lair is taken over by a new dragon, the latebrangel will serve the new dragon instead, but only if the new dragon intends to make that place its primary lair. Latebrangels are possessive and self-serving beings and will actively seek the destruction of their resident dragon and the resurrection of the previous resident if the new resident supplies it with less potentia than the previous resident.

A dragon will select from their territory their strongest warriors and spellcasters for the defense of their lair. Usually these will consist of draigfolk warriors and alwyvern spellcasters, but a few especially powerful dragons employ speakers and demiwyrms as lair guards. The guard will have enough people in its ranks to repel an army led by an enemy dragon.

Dragons are divided into four classes. Elemental dragons, force dragons, composite dragons, and mind dragons.

Elemental dragons are the most common dragon class as well as (usually) the least threatening. Roughly 85% of all dragons are elemental dragons. Elemental dragons have control over some fundamental property of their surroundings, such as heat, cold, electrical current, air water, and earth.

Force dragons are among the stronger dragons, and are the second most common. Roughly 14% of all dragons are force dragons. Dragons of this type have control of some derived property of their surroundings, such as light, darkness, gravity, radiation, sound, and speed.

Composite Dragons are the strongest type of dragon in terms of raw combat potential. Roughly 1% of all dragons are composite dragons. Dragons of this type may freely rearrange the chemical structure of their surroundings, although typically the range of this ability is very, very short (less than one inch). Domains that fall within the composite subclass include poison, explosive, corrosive, alloy, and meta.

Mind dragons are the most threatening type of dragon despite being the weakest physically. Fewer than two dragons per thousand are mind dragons. Dragons of this type may freely rearrange the minds of those near them. A mind dragon can completely read someone's thoughts with trivial ease, and freely wipe memories, add false memories, and even alter a person's entire personality. It is impossible to fight a mind dragon directly and win. The moment the mind dragon becomes aware of you, it is over.

Dragons have an innate ability to shapeshift, which is generally first manifested at the age of 10, and which is generally mastered by the age of 40.

This is not to be confused with Illusion, as the dragon is not merely masking their appearance, but physically altering their body.

Mass is given off from a dragon that is shapeshifting to a smaller size, mostly in the form of carbon dioxide and steam. For this reason, dragons will not shapeshift indoors.

For a dragon to return to its full size, the fastest way for it to do so is for the dragon to rapidly regain their mass from inhaling smoke, which is largely comprised of steam and carbon dioxide. If a dragon intends to return to full size, usually the dragon will find or create a bonfire and fly above it, taking in the smoke to recreate its body. Even in ideal conditions, this process may take hours for a younger dragon, or months for an extremely large dragon.

Though quite capable of doing so, most dragons are not willing to shapeshift to a size smaller than a Sape, for fear of being captured.