Dragon

The Dragon species consist of purebloods, sub-species, and dragon emperors.

Higher class dragons have their territories that they stay within, but they mess up the ecosystem up without a second thought. The dragons that people use are sub-species dragons mixed with weaker monsters.

Dragons have a natural hostility towards Filolials and vice versa.

Pureblood
The first species of dragons that refer themselves as dragon emperors. They are mentioned to have manners and are well-behaved as long as they don't go into heat.

However, when they do go into heat, they have absolutely zero regard for race and they'll even try to mate with humans.

Tyrella
The only mention of sub-species of dragons that do not possess wings or the ability to fly. This particular sub-species is often referred to as Knight Dragons, and are generally used as transport vehicles similar to horses.

Flying Dragon
A sub-species of dragon specialized in their flying abilities. However, they lack any actual combat abilities. These particular sub-species were a mix of dragons and other monsters capable of flight.

Wyr
A sub-species of dragons that value devotion highly and are one of the most loyal types of dragons. These particular sub-species are a mix between Purebloods and Tyrellas.

Zombie Dragon
The animated corpse of a dragon emperor still possessing one the Dragon Emperor Cores. The dragon possesses strong regenerative abilities and breaths poisonous gases from its mouth, once the core is removed from its body, the dragon will return to its skeletal form.

Tyrant Dragon Rex
The result of a non-dragon species possessing a fragment of the Dragon Emperor Core. This particular dragon emperor is an enigma and seemingly mutated over time gaining the traits of a dragon.

The Dragon Emperor
The legendary king of the dragons that supposedly fought the queen of the filolials. It's just a legend and it's questionable whether either creature actually existed. Kizuna also mentioned there's one in her summoned world.

Water Dragon
A pureblood species and the guardian of Q'ten Lo.

Trivia

 * The Dragon Emperor Core taken by from the Zombie Dragon was split three different ways, the first was eaten by Filo, the second was absorbed by the Legendary Shield and the third was crafted into the Barbarian Armor.
 * Gaelion would later absorb one of the fragments, specifically the one removed from the Barbarian Armor. He now shares his body with the Original Gaelion due to adsorbing this fragment.