Gretti was a young man on board a spaceship in an ancient caravan of "space gypsies". The caravan was threatened by a black hole that bridged the gap between the Anti-Matter Universe and ours. The Green Lantern of Uxor, known as the Green Man, had come to close the hole and save the travelers. Although they could not save themselves, the people of the caravan refused the Green Lantern's help. In accordance with the ways of their ancestors, no one outside of the group was allowed to aid the caravan. The gods had placed the evil in their ancient path, and they must meet it bravely and alone.
In order to help the caravan, the Green Lantern gave Gretti a power ring. The young man was arrogant and impatient, but after the Green Lantern showed him what to do, Gretti closed the hole and saved his people. They returned to the caravan, with the young man regarded as a hero. The Green Lantern of Uxor left Gretti under the watchful eye of his grandmother.
While traveling with his people, Gretti continued to serve the universe as a Green Lantern even after the Green Lantern Corps was reestablished after its destruction. However, he was never compliant with its rules that he patrol his assigned sector. He patroled wherever his people's caravan took him, which was well beyond his assigned sector, Sector 2828. The idea of remaining in one place was simply against everything he believed. Because he did continue to serve well as a Green Lantern, his wandering ways were overlooked by his superiors. His ways did add to the frustrations of his partner Green Man and of Stel, who acted when needed as Green Man's partner in Gretti's persistent absence.
Agent Orange
Gretti was ordered back to Sector 2828 by his superior Green Lantern Salakk. The Guardians along with a squad of Green Lanterns were already in route to Okaara to deal with the emerging threat of Agent Orange; aka Larfleeze. The Vega System was declared to no longer be off-limits due to the actions of Larfleeze, keeper of the Orange Light of Avarice. As the Green Lantern of the sector, he was expected to be the local guide and liason in the Vega System. Even though it went as Going against his beliefs, he met them on the planet Okaara to participate in the arrest of Larfleeze. The Guardians ordered Larfleeze to come out of his palace disarmed without his ring. Larfleeze chose not to surrender and unleashed his Orange Lanterns. Gretti found himself attacked by four Orange Lanterns each one pulling at a different limb; each one demanding Gretti had something that belonged to them. He could not understand what they wanted and despite his struggling against them the Orange Lanterns ripped him apart into several pieces.
Moments after Gretti's death the Orange Lantern Glomulus exclaimed Gretti's ring belonged to him and before the Green Power ring could seek out a replacement Glomulus swallowed the ring, destroying it. The Orange Lantern Corps' standard protocol went into effect and the Orange Light of Avarice consumed and stole Gretti's identity transforming him into the newest member of the Orange Lantern Corps. Gretti became a mindless drone carrying out Larfleeze's orders and attacked John Stewart.