Created by artist John Byrne and writer Marv Wolfman, the character first appeared in October 1979, and is a herald of cosmic entity Galactus and enemy of the Fantastic Four.
Terrax travels with Galactus to Earth and, while his new master battles the Sphinx, attacks the Fantastic Four—still resenting the heroes for their role in his transformation.
Shortly after being transformed into Galactus' herald, Terrax fled from his master and overthrew the ruling body of a small, unnamed planet.
Utilizing his power, Terrax levitated the entire island of Manhattan into earth orbit and used the lives of its millions of inhabitants to bargain with the Fantastic Four.
An unidentified passerby took Terrax's broken form, unknown to both the Fantastic Four and the Avengers, who were present at the site, to a nearby hospital.
[7] Tyros defeated the Fantastic Four at a shopping mall and, detesting the fact he was in the service of any master, he turned on Doom and immobilized the Latverian monarch in his armor.
[9] In an Avengers annual Terrax is temporarily resurrected to become a member of the second Legion of the Unliving by the Elder of the Universe the Grandmaster.
[13] Morg eventually wishes to retrieve his weapon and battles Terrax until both are briefly captured—together with several other extraterrestrial characters Gladiator and Beta Ray Bill—by the entity Tyrant.
[14] Terrax guest stars in the limited series Cosmic Powers, in which Tyrant is confronted and thwarted by the Titan Thanos.
[18] Terrax appears in the Annihilation storyline, being initially captured by the forces of Annihilus before escaping with the Alien Skrull Paibok.
[22] While he was killed by the Phoenix Force, Tyros was eventually resurrected at some point and was found by Drax the Destroyer when the later crash landed on an unnamed planet.
[23] The events that led to his resurrection are unknown even for Tyros, but he suspects that the Phoenix's energy that killed him also might have restored him back to life.
Thane eventually learned about this, and deceived his allies (the Champion, Starfox and Nebula) into helping him invade Terrax's warship to steal the egg.
[26] Tyros is an alien with a genetic mutation that gives him the limited psionic ability to manipulate rock and earth molecules.
After being transformed by Galactus's Power Cosmic, he can perform near-limitless feats, such as moving asteroids, meteors, and even whole planets from space at high speeds, affect tectonic plates to cause earthquakes and create chasms, or levitate large landmasses miles into the air.
Like all Heralds, Terrax has immense strength, stamina, durability, speed, agility, reflexes, and lifespan, as well as hypersonic flight, energy control, and sustained metabolism.
When this Earth started to collide with Earth-616 due to an Incursion, the Illuminati traveled to that reality to see if they could save the people there before destroying the world.
Terrax was eventually defeated and captured but not in time to stop Galactus, who consumed the Earth-TRN267, averting in the process the Earth-616's destruction.