King Ymiron

King Ymiron was the king of the vrykul in Northrend and previously lay sleeping within Gjalerbron. His people, the Dragonflayer Clan, are still fanatically loyal to him. Having recently proven himself to the Lich King, he was converted to the undead and was the King of the Vrykul.

History
The Anguish of Nifflevar, the Azerothian Heroes uncovers an event of the distant past, where King Ymiron declares that the old gods - the Titans - had abandoned them, and pledges to protect the Vrykul race. His first act is to declare that aberrant children, evidently precursors to humans, be destroyed to preserve the Vrykul racial purity. The Echo of Ymiron had earlier shown that some families had acted to preserve these children despite the proclamation. This decision makes King Ymiron indirectly responsible for the creation of what is now the human.

Recent
Ymiron was slain by forces of the Grand Alliance and the New Horde in battle within Utgarde Keep, it is not known whether a member of the Horde or Alliance got the final blow.