Omega was an unmodified, yet enhanced human female clone created from the genetic template of the Mandalorian bounty hunter Jango Fett who lived in the years following the Clone Wars. Originally created as a pure genetic replication of Fett, she was a medical assistant to Nala Se and spent her days working in Tipoca City on the clone homeworld of Kamino. When the war ended, she took an interest in Clone Force 99, who had returned from a battle on Kaller. Later, when Wilhuff Tarkin arrived on Kamino to assess the clone troopers, she joined Clone Force 99 and escaped Kamino.
Omega accompanied Clone Force 99 on their subsequent visit to the Lawquane’s Farm on Saleucami, which was her first time away from Kamino. There, she made friends with the Lawquane children, Shaeeah and Jek, and helped secure the family’s escape by delivering forged chain codes to them so they could board a transport. She was given an opportunity to go along with them on the transport, but decided to remain with Clone Force 99.
After Omega drew the attention of the bounty hunter Fennec Shand during the Bad Batch’s supply run on the moon Pantora, the group made their way to an informant named Cid, whom Echo knew that the Jedi trusted during the war. Omega was given a comlink and the group pulled off a job on Ord Mantell in exchange for information on Shand as well as credits. The Bad Batch would begin working for Cid, with the group pulling a job on Corellia shortly after their first successful work.
Omega would soon meet Captain Rex, a former soldier in the Grand Army of the Republic and associate of the Bad Batch. When Rex realized that the group still had their inhibitor chips, he implored them to get them removed. Omega and the others would join him on Bracca so the rest of the group could undergo a procedure inside a downed Venator-class Star Destroyer and get the chips removed. After Rex departed, the group would soon be discovered by the Empire. After being pursued by Crosshair and his forces, Omega was eventually kidnapped by a third party: the bounty hunter Cad Bane. She would eventually escape Bane when he landed at a facility on Bora Vio to collect his payment, and after evading Bane and the recently arrived Shand, she was rescued by the other members of the Bad Batch.
When Hunter was captured by the Empire on a mission on Daro, Omega and the others returned to Kamino to rescue him. Omega assisted in freeing him from Crosshair and his squad, but when the Batch tried to flee, Imperial Star Destroyers bombarded Tipoca City, sending it sinking to the ocean floor. The group, along with AZI-3 and Crosshair, followed Omega through the Kamino tube system back to the ship, but when the elevator was broken, the group floated to the surface in cloning pods, guided through the debris by AZI-3. When the droid sacrificed the last of his power to save Omega, she dived into the water after him and rescued him thanks to Crosshair saving them both. When the Batch offered Crosshair a place among them once again, he declined. Omega thanked him for saving her and reminded him that he was still their brother, and hers, before leaving Kamino with her squad.