It is said that the quadrupedal heroes of Unova - Cobalion, Terrakion, and Virizion - each carried their own Wormadam in their fur. These Wormadam existed in a symbiotic relationship with their divine protectors; they fed off parasites and served as a secret weapon in battle. Yet when these heroes traveled to the Hall of Origin to petition Arceus to be made full gods, they tripped over the branches and roots of an enormous tree. Although the demigods got up quickly, all three Wormadam were knocked loose into the forest, unnoticed by the pokemon who carried them.
Their petition was denied. Some claim it was because the heroes were not strong enough, but others say Arceus' true reason was that the Wormadam had fallen from them. The three returned despondently to Unova, too disappointed to notice the loss of the smaller pokemon on their backs. These Wormadam established a colony in Sinnoh's trees. They had many children, but they had lost their immortality when they fell, and in time they too passed away. Yet their descendants did not forget their heroes; the three formes they are seen in today reflect the three pokemon who carried them to this land.
The Wormadam today live their lives in honey trees, for honey is made from Combee nectar, which is beloved not only by the gods themselves but by all who aspire to divinity, from the three heroes to the Wormadam themselves. And these pokemon watch the sky constantly, not only for their many flying-type predators, but for the hope that the great heroes of Unova will someday notice what went missing, and come back to claim their riders of old.