History: Tyros was originally the dictator of the small city-state Lanlak on the world of Brij (sometimes translated as Terran), a moon of the gas giant Marman in a solar system eighty thousand light years from Earth. Tyros ruled through the use of force, his limited power over earth and rock. This power, which apparently was a mutation unique to Tyros, enabled him to animate constructs of stone which would patrol his kingdom maintaining his firm control. Tyros loved power and conquest, and led a life of debauchery and violence. Somehow, he came to the attention of Galactus, the world devourer. Galactus had been seeking a new herald to guide him to fertile planets which he needed for sustenance. The space being surmised that the common fault in most of his former heralds was that their moral values prevented them from fulfilling their duties. For a new herald, Galactus sought an individual who would have no compunction in finding worlds for Galactus to render lifeless.
When the Fantastic Four came to Galactus to ask him for aid in the battle against the Sphinx, Galactus agreed, but only with the condition that the Fantastic Four would journey to Brij and subdue Tyros for him. The Fantastic Four reluctantly did this, and in doing so, they freed the city of Lanlak from Tyros's rule. Brought before Galactus Tyros was exposed to Galactus's cosmic power, and was transformed into Terrax the Tamer. His minor control over stone was augmented to an incalculable degree. Now, he could affect all matter of rock and stone on nearly a planetary scale. His body was changed so that it would withstand the vacuum of space. Finally, Galactus gave Terrax a weapon called the "cosmic axe," capable of generating waves of cosmic force.