Emperor Dragon

Emperor Dragons are the wisest, largest, and most powerful of all their kind -- only they can truly compare with the mighty Kalgalanos, the Black. Today, Emperor Dragons are beyond rare, and the few that have survived spend most of their time hidden away and asleep. As legends have it, the few remaining Emperor Dragons spend their time guarding their vast treasure hordes, piled wealth that has been many millenia in the gathering. All Emperor Dragons love gold and riches, and any of their hordes is said contain wealth equal to the treasury of the very greatest of Dwarf kings. Accordingly, and Emperor Dragon seldom likes to venture far from its lair, in case of theft, but at need the great beast will unfurl its ancient wings and fly down from its mountain lair to feed and plunder.

There are many tales of Emperor Dragons, including the legendary Skaladrak Incarnadine, who slew many armies of Dwarfs in the lands around Karak Kadrin, and Skulex the Great, an immense beast that still resides unchallenged in the peaks of Norsca. An Emperor Dragon in battle is a terrible sight, capable of laying waste to whole armies, destroying towns, razing crop fields and consuming herds of livestock. Once an Emperor Dragon is provoked to battle, there are few creatures or heroes capable of defeating one in any semblance of fair combat.

Indeed, the only recorded occasions on which Emperor Dragons have seen defeat have been when many thousands of foes have been arrayed against them, or some sorcerous trickery was employed. If few warriors can be counted on to defeat an Emperor Dragon, there are still fewer individuals capable of taming one. Even the famed Dragon Riders of Caledor were never able to tame the oldest and greatest of the Emperor Dragons.

Source

 * Warhammer -- Storm of Magic (8th Edition) -- pg. 120