Greer was a human clone of the bounty hunter Jango Fett, created for service in the Galactic Republic's Grand Army of the Republic. By around 18 BBY, Greer had joined the Clone Underground movement which sought to liberate their clone brethren from the Galactic Empire. Greer traveled to Pantora with Samson, Howzer, Nemec, and Rex to help protect Senator Avi Singh during his secret meeting with Senator Riyo Chuchi on Pantora. During the mission, Greer was choked unconscious by the Imperial Clone X trooper CX-1.
Greer was created on the planet Kamino as a clone of the human male bounty hunter Jango Fett to serve in the Galactic Republic's clone army during the Clone Wars against the Separatist Alliance. At some point during or before 18 BBY, Greer joined the Clone Underground resistance network. During that time, Greer was deployed to the planet Pantora alongside Samson, Howzer, Nemec, and Rex on a mission to protect Senator Riyo Chuchi and Senator Avi Singh while they held a meeting regarding former Republic and Separatist worlds' growing discontent with Emperor Palpatine and the Empire. Greer was tasked with standing guard over the kitchen for the building where the meeting took place.
While the meeting was in session, Imperial Clone X trooper CX-1 was already on the planet, and had been stalking senator Singh while he was escorted to the building. The assassin entered the city's maintenance tunnels, and made his way to underneath the building. The assassin exited the tunnels though a hatch located in a small room in the building's kitchen area, and opened the door leading outside the room. Standing outside the door was Greer, who the assassin subsequently attacked and choked unconscious. Outside the building, Howzer who was stationed on sentry duty outside asked both Samson and Greer for a status report. While Samson replied, Greer did not, and a concerned Howzer asked Rex to check the kitchen. Rex spotted the assassin intruder, and foiled his attempt to kill the senators. Both Rex and Nemec chased the assassin back into the maintenance tunnels, where they saw Greer's unconscious body laying on the floor.
Greer wore Phase II clone trooper armor with customized green markings. Additionally, he adorned a blaster holster on his left leg, a pouch on his right leg and ankle, and a sheath on his left wrist. Greer wielded a vibro-knife, a DC-17 hand blaster, and a DC-15A blaster carbine.
Greer appeared in "Infiltration," the sixth episode of Star Wars: The Bad Batchs third season, which premiered on March 13, 2024 on Disney+.