Wheeljack is a former member of the Wreckers, a combat unit that operated outside the normal chain of Autobot (faction of robot alien race who fights for peace and freedom) command. They took on dangerous missions no one else would. Trained specifically for battle and combat, Wheeljack is one of the roughest Autobots around and has an attitude to match. When we first meet Wheeljack, he's clearly a rebel, focused mainly on doing as he sees fit and has little respect for Autobot leader Optimus Prime. After some time he gain respect for Optimus and becomes a team player.