Frost Wyrm Skull Shield

This ancient Frost Wyrm skull has been equipped with handles, turning it into a powerful shield. Increases armor by 2 when worn and reduces Magic damage dealt to the Hero by 33%.

This unique shield was carved from the flattened crown of a white dragon's skull. The bone has been hardened and enhanced with an intricate steel framework interlaced with unidentifiable runes from an unknown maker.

Source
Kael and Lady Vashj can find this in The Dungeons of Dalaran, chapter 3 of the Frozen Throne alliance campaign, Curse of the Blood Elves.