Clan Drakebeard

The most famous clan of Karak Kadrin, and indeed one of the most well known in all of the Karaz Ankor, is the Drakebeard Clan. The most noble of its line is none other than Ungrim Ironfist, King of Karak Kadrin. As Ungrim's only son, Garagrim, was slain, Ungrim is now without a direct heir — a fact not lost on the rest of the noble sons of the Drakebeards. The clan thanes each seek to lead throngs to glory and thus catch the eye of their warrior king. As they are a grudge-ridden folk, even for Dwarfs, and Peak Pass is full of perils, there is no shortage of foes, presenting constant opportunities for the fiery-hearted thanes to prove themselves. Their symbol, the writhing Dragon with Grimnir’s seal, appears on their banners, while the deep red of their shields marks them as loyal to Karak Kadrin.

Source
pg. 29
 * Warhammer Armies: Dwarfs (8th Edition)