Tyranastrasz (aka Tyrannistrasz) was the first consort of the Dragonqueen Alexstrasza. He was ancient and wise, but also a very large powerful wyrm. He was known as "The Scholarly One" among the red dragons. Tyranastrasz was Alextrasza's majordomo in all affairs.
Tyranastrasz was heavily involved in the War of the Ancients. He willingly imparted a piece of himself into the Demon Soul at his queen's request, and was present when Neltharion betrayed the other flights and turned the talisman against them. Tyranastrasz later came at his queen's call, along with another unnamed consort, to safely move the unconscious youngest consort, Korialstrasz, after a battle with members of Deathwing's flight. In the final battle, Tyranastrasz commanded the forces of the Red, Green, and Bronze flight aiding the defenders of Kalimdor against the demonic swarms, while his queen, along with Ysera and Soridormi, fought the Highborne loyal to Azshara and Sargeras over the Well of Eternity.
He was captured along with Alexstrasza by the Dragonmaw clan during the Second War and forced to mate with her in order to produce offspring for the clan to ride into war. Tyranastrasz was an old dragon before he was captured, older even than Alexstrasza, and the constant strain of his captivity hastened his death. He died by the hands of Deathwing just before the Dragonqueen herself was liberated. His skeleton currently lies near Grim Batol, but his skull was found by the Explorers' League and taken to the Hall of Explorers museum in Ironforge. The plaque on the display (spelling his name as "Tyrannistrasz") reads:
The remains of the gargantuan red dragon were found in the Wetlands shortly after the Battle of Grim Batol. Tyrannistrasz was rumored to have been the elder consort of the Dragonqueen, Alexstrasza.
Day of the Dragon implies that Tyranastrasz was her final consort, whom the orcs managed to capture along with Alexstrasza, but War of the Ancients clearly establishes that he was alive during the Burning Legion's invasion and was Alexstrasza's primary consort. During Day of the Dragon, Nekros Skullcrusher had failed to capture and was unaware of the existence of Alexstrasza's then-youngest consort, Korialstrasz, explaining why Tyranastrasz was referred to as her final consort. Since both books are written by Richard A. Knaak, it is safe to say that Tyranastrasz was the primary consort and is many tens of thousands, if not more, years old.