"The mighty Wyverns and the powerful Wyrms are notorious for the enmity they possess for one another.
The reasoning for this is simple; like all dragons, both the Wyverns and the Wyrms are driven by their instinctive and natural greed. Both hunger for the same prey, lust after the same treasure, and prefer the same environments to which to make their territory.
When such resources are limited, as it is usually the case, and neither are willing to compromise or share, conflict was inevitable.
Long before even the rise of the mortal races, members and clans from both species have been constantly at war with one another, struggling, fighting, squabbling and bickering with a fierce passion and intense hatred, fuelled by their inherent predisposition to violence. It has progressed to the point that it has become deeply rooted in their history and culture, with neither side willing to accept anything less than total destruction of the other.
Yet, because both wyverns and wyrms equally matched in flight, magic and physical strength, even after generations of conflict, neither kind have decisively triumphed over the other, and was expected to remain so for countless more generations to come, were it not for an unexpected new player in their conflict..."
--- The Dragons: A Compendium, a book on the dragons published in one of the human kingdoms.