Draconia

The dragons live in rival colonies and are extremely territorial. The young dragons follow the lead of their elders and when the territory of a colony isn't enough for everybody, the colony splits in two and they fight to know which side can stay and which one has to find a new place to establish their new territory.

The territories of smaller dragons overlaps with the territory of a bigger one they serve. It's only when dragons of same strength compete for the same territory that a territorial war occurs.

They mostly live on the biggest continent of Lostira but in the recent centuries they started to migrate to other lands across the world. Moreover, due to their high adaptability, it wouldn't be surprising that some dragons live underwater.

This is primarily a calculated estimation, but the dragon population is estimated to exceed 40 million. Among them, there is 1 Apocalypse dragon (Keisar, 10 km), 0 Titans (1 km), approximately 10 Colossi (500 m), 100 Ancients (100 m), 10,000 Elders (50 m), 1 million Adults (25 m), 10 million Younglings (10 m), and 30 million Hatchlings (5 m).

To complete this hierarchy, we can consider an additional category: Cosmic. This category encompasses dragons so immense they cannot live on a planet, reaching this stage only after 1 million years of existence.