Retrax started life as a decpticon tank drone created by shockwave. This non sentient drone followed Optimus prime and the autobots down to the chamber of vector sigma when the aerial bots were given life. Vector sigma sensed this drone and gave it life as well. Retrax stayed in hiding deep in the tunnels of cybertron untill he figured out what had happened to him. Alpha Trion appeared to him in numerous visions and he explained these things to him. Retrax is a ground artillery unit in alt mode.