Dragonology

Overview

The word Dragon is, within the Multiverse, a broad term that refers to all the beings with reptilian morphology that come from the draconic lineage. Creatures in Runeterra that fall under this term can be split between Terrestrial Dragons, Primordial Dragons, or Spirit Dragons by way of their origins. The "sub-species" mentioned above are not genetically linked with each other, but usually do share physical appearances.

Physiology

Dragons are a special group of reptiles that may reach near-giant sizes and often with great lifespan. Dragons of Runeterra have great species diversity, with over 200 types of talking dragons being present in Ionia alone according to Irelia.
The firstborn female dragons of certain dragon bloodlines have elemental rune shards within them, which gives them their elemental powers. There are numerous types of elemental dragons as there are elemental magic. While dragons reside across Runeterra, most elemental drakes live in Ixtal and can rarely be found elsewhere.
Curiously, the abandoned ruins scattered throughout Ixtal are home to a surprising number of dragons. These terrifying creatures have not fought alongside mortals since the last days of Shurima's war against the Void—now, for the most part, they seem content just to be left alone.

Terrestrial Dragons

Terrestrial Dragons are the most commonly found dragons on the material plane and can vary greatly in intellect and size. There is a big divide here between those that are just sentient and those that are also sapient. Those in the first category would be simple hunters that lack intelligence and are more animalistic. Wyverns and screeching dragons are examples of dragons that would fall into this category. The latter category is what most people would think of closer akin to chromatic/metallic/gem dragons and dragon turtles that hoard treasure. While they do exist here, their dominance is generally shadowed by the Primordial and Spirit Dragon counterparts.

Primordial Dragons

Primordial Dragons originate from the elemental planes of air, earth, fire, and water. Their kind informally answer to each realm's Greatwyrm who in turn bows to the Elder. It is these Greatwyrms and Elder that the people of Ixtal made a pact with to become the dragonborn. Primordial dragons have the power to influence their surroundings and, once powerful, can command the elements themselves.
While there are a number that live in the Material Realm, they usually stay away from civilization and prefer to maintain their own domains. It is thought that many more make their homes on the elemental planes. Unfortunately, not many scholars make their way over (successfully) to study and learn more about them.

Spirit Dragons

Spirit Dragons come from the realms beyond and come in a much wider variety than the other dragons. While most are very similar to their kin from the other planes, others, particularly the ones from the Astral Realm, take on more abstract forms. Primordial dragons may be hard to study, but these are nearly impossible. Don't expect to find much information outside of speculation in your local library.

Camavoran Dragons

While unknown to most, a few residents of Bilgewater have caught sight of this creature, and even fewer lived to tell the tale. Once magnificent beings, the dragons in Camavor were infected by the Black Mist, twisting and warping them; turning them into nightmarish versions of their past selves.

Half-Dragons

Half-Dragons are an extremely rare instance where a dragon's offspring comes out partially humanoid. This phenomenon occurs when a dragon egg is taken from its nest by a humanoid. When the egg eventually hatches, it no longer can fully identify with its draconic heritage. Although, they can still switch into a draconic form, equally as powerful as their draconic parent.