Gregor

"You will be remembered, Captain Gregor. We'll take your heroic story back to the Republic, and we will watch for your return."

- Colonel Gascon

CC-5576-39, nicknamed "Gregor", served as a clone commando and a clone trooper captain of the Grand Army of the Republic, fighting the Clone Wars. During the battle of Sarrish, he was forced to retreat into space where he ended up crash landing on Abafar. The crash caused him to suffer from amnesia and he was hired by a Sullustan named Borkus who had him work as a dishwasher in a local bar until he regained his memories after Colonel Meebur Gascon showed the commando information to him. He was thought to be killed in an explosion trying to protect the colonel and his companions in a firefight against Separatist droids, but survived, although he suffered from brain damage, causing him to partially go crazy. 15 years after the end of the Clone Wars, Gregor was still alive and was living in a modified AT-TE on Seelos with Captain Rex and Commander Wolffe.

The Clone Wars
Gregor was in command of Foxtrot Group, an elite squad of clone commandos, but was reported missing in action during the Battle of Sarrish. He ended upon Abafar with amnesia and was given a job as a dishwasher at the Power Sliders diner by Borkus for nothing more than room and board. After Colonel Meebur Gascon and his team of droids crashed landed on Abafar, they helped him to recover his memory and he in turn helped them to escape, but was left alone on the planet surrounded by hostile forces and facing near-certain death. He seemingly sacrificed himself after shooting containers of rhydonium to destroy the droids which would have shot down Gascon's shuttle which had been fleeing. He survived however, and somehow made his way back to the Republic. Gregor was then promoted to Commander for his bravery.

Under the Empire's reign
Gregor survived the Clone Wars and at some point removed his control chip. In the years after the Empire's creation, Gregor was living with Captain Rex and Commander Wolffe in a modified AT-TE on the planet Seelos. Unfortunately his brain took a hit and as a result, he suffered from episodes of mild insanity.

Five years prior to the Battle of Yavin, the clones were approached by the crew of the Ghost, who were looking for information on abandoned military installations for the Rebel network. When Kanan Jarrus identified them as clones, Wolffe, in turn, recognized him as a Jedi and let off a few shots. Gregor eagerly raised his rifle but Rex calmed the situation. When Ezra Bridger explained that they were sent by Ahsoka Tano, Rex welcomed them as friends. Later on, Gregor encouraged the Lasat Garazeb Orrelios to help the clones hunt for joopas. But he later reveals to Ezra that Zeb was in fact the bait, resulting in the Lasat being swallowed by the joopa, whom Gregor nicknamed Big Bongo. After managing to kill the joopa, Zeb was none to happy to learn that he was bait, but was calmed when Gregor pointed out that he helped catch Big Bongo.

While settling down for dinner, Sabine discovered that one of the clones, Wolffe, had contacted the Empire. While Gregor and Rex had grown to trust the Ghost crew, Wolffe wanted to protect his comrades from being persecuted by the Empire for harboring these rebels. When confronted, Wolffe admitted his wrongdoing and accepted Rex's reasoning that the rebels were their friends. After discovering and destroying an Imperial probe droid, the clones and rebels prepared for the impending Imperial assault. While Kanan tried to convince the clones to come with them, Rex was adamant that he and his comrades would stay behind to hold the Imperials back while the rebels escaped.

The rebels reluctantly departed on their auxiliary ship Phantom to rendezvous with the Ghost in space. Shortly later, a force of three AT-AT walkers led by the Imperial Security Bureau Agent Kallus, a perennial foe of the crew of the Ghost. While outnumbered and outgunned, Gregor and his companions faced off against the Imperials in their lone AT-TE walker. At Ezra's urging, the rebels returned to rescue the clones and succeeded in defeating the Imperial force, forcing Kallus and his men to flee into the desert. After that, Gregor and his fellow clones saluted Kanan and his Padawan, and Rex agreed to join the Rebellion whilst Gregor and Wolffe stayed behind on Seelos, taking the remaining AT-AT walker for their new home.

Behind the scenes
Gregor was first seen in "Missing in Action," an episode of the fifth season of the Star Wars: The Clone Wars television series. A preview clip featuring Gregor was later shown at Celebration VI. He is voiced by Dee Bradley Baker. A trailer for the show's fifth season includes Aurebesh on Gregor's profile notes indicating that he went missing in action during the Battle of Sarrish.

During the episode, a hologram showing Gregor's military records was displayed in Aurebesh after R2-D2 scanned his identifying code. As well as displaying Gregor's status as MIA during the Battle of Sarrish, it displayed 'Sgt 1st Class', '212 Attack Battalion' and 'Foxtrot Group', as well as Gregor's height and weight. The designation of Sgt 1st Class contradicts Colonel Gascon stating that Gregor was Captain, despite the fact that Gascon was going off of the hologram.

The markings on Gregor's helmet were inspired by the hash-marks that Boston Bruins goaltender Gerry Cheevers stenciled on his mask to denote the stitches he would have gotten had he not been wearing protective gear.