The proto-dragons were sort of the early version before dragons really evolved into the sapient, beautiful majestic creatures that they are known today.[1]
Galakrond, a massive proto-dragon,[2] was the "progenitor of dragonkind". From him, the Titans created the Aspects.[3]
In World of Warcraft: Wrath of the Lich King, several proto-drake mounts are available as rewards for various achievements, as well as a few that drop from mobs and bosses:
Though many proto-drakes are present in Northrend, no fully matured proto-dragons are to be found, with the possible exception of Broodmother Slivina and Veranus.
A Proto-Drake would take decades to mature. Most humanoid creatures in Azeroth would never live to see a Proto-Drake go from hatchling to fully mature Drake.
Speculation
This article or section includes speculation, observations or opinions possibly supported by lore or by Blizzard officials. It should not be taken as representing official lore.
Proto-dragons have a considerable likeness to the devilsaurs and pterrordax that inhabit Un'goro Crater, meaning that the dragons themselves could have evolved from the dinosaurs.