Morg was a simple executioner on the planet of Caraner. It was a medieval world of war and retribution, until the day the world devourer Galactus consumed it. The selfish executioner was spared the fate of the other inhabitants of Caraner, because he foolishly opposed Galactus. The world devourer selected the ruthless Morg as Herald. He would later replace the Earth girl Nova (Frankie Raye).
Morg lacked the compassion for life that Frankie Raye and the other Heralds possessed. Instead of finding dry barren planets for Galactus to feed, Morg chose worlds that were teeming with life. On the planet of Bastion he discovered an immense power source that was known as the Well of Life. Morg bathed in the waters of the well. He gained tremendous mystical energy, which augmented his already enormous cosmic power. He eventually led Galactus to the planet to feed.
Due to his low morality, Morg’s position as Herald was contested by the Silver Surfer, former Herald of Galactus. The Silver Surfer gathered his fellow ex-heralds Firelord, Air-Walker, Terrax and Nova to confront Morg. Nova lost her life in the battle. Terrax the Tamer brutally defeated Morg in a vicious cosmic confrontation and kept the executioner’s ax. Galactus resurrected Morg once more but reduced his power level, making him equal to the other heralds.
Galactus allowed him to seek out Terrax to regain his ax. Morg found and battled Terrax, but they were ambushed and captured by servants of Tyrant, the long time enemy of Galactus. They were imprisoned in Tyrant's floating fortress along with Beta Ray Bill of Asgardian might, the leader of the Shi'ar Imperial Guard, Gladiator, the Silver Surfer, the cosmic half-breed Jack of Hearts, and Ganymede of the Spinsterhood. Upon Galactus' arrival all the warriors were released except for Morg. Galactus, unready to battle Tyrant, left Morg in the servitude of his enemy.
Despite Tyrants attempts to corrupt him, Morg remained loyal to Galactus. Tyrant placed a device on his head allowing him to control Morg's mind and will. Morg was accidentally freed when the mad Titan Thanos in allegiance with Terrax and Ganymede assaulted Tyrant. Morg regained his ax and returned to Galactus.
When Tyrant confronted Galactus directly, Morg wielded the ultimate nullifier in defense of his master. However, a minion in the thrall of Tyrant attached itself to Morg’s arm and the nullifier, combining them with the weapon. Neither of them proved capable of controlling the nullifier’s power. As the device powered up to detonation, Morg managed to free himself somehow, sliced through the hull of Galactus’ ship and fled the scene.
Despite his great speed, he was caught in the detonation and gravely wounded in the process. He healed from his wounds only to be apprehended and dissected by the forces of Annihilus during his invasion of the positive universe. Morg was not as fortunate this time, even with the combined might of the Power Cosmic and the mystic energy from the Well of Life; he was unable to escape the Annihilation conflict alive. Once again Morg has been erased from the cosmic landscape.