|Powers and Abilities||Power Cosmic|
|Team Affiliations||Herald of Galactus|
Tyros was the ruler of a planet. When Galactus met him, he was impressed and thought his heartless nature would make him an excellent herald. When Galactus gave Tyros the Power of Cosmic he took the name Terrax. Terrax joined Silver Surfer and Firelord as Heralds.
The three went to Earth where they fought the Fantastic Four as they prepared the planet for Galactus' consumption. However, Silver Surfer betrayed them and helped fight them off. Terrax and Firelord continued to help Galactus while Silver Surfer was exiled to Earth.
While in space, Terrax and Galactus were approached by Mister Fantastic and Thor. They told them that Ego was threatening Earth. The two cosmic beings teamed up with the Earthlings to stop the living planet.
Afterwards, Terrax wanted to destroy Galactus. He lured the planet eater to the planet and got him to fight the heroes of Earth until he was weak. However, Galactus was still powerful enough to destroy his traitorous herald.