Wreck-Gar is the leader of his people on the planet Junkion. His mind reflects the ramshackle, cobbled-together nature of his world; he's rambling, fragmented, obsessed with turning scrap into new life, and does it all with a bellowing voice. Though simple and singleminded, he's also an extremely tough, stubborn and resilient being, not to mention a surprisingly competent leader of his hard-bitten, survivalist race. He turns into a mobile trash compactor.
Leading a scavenging party across the surface of his planet, Wreck-Gar stumbled across a party of Autobots. Believing them to be nonfunctional, Wreck-Gar ordered his Junkions to begin cutting them up, only for a fight to ensue. When he realized his mistake, he let them go and interrogated Optimus Prime as to why they had come, although his highly eccentric mannerisms confused the Autobot leader. The Matrix of Leadership temporarily cleared his mind, though, and he soon pledged he and his Junkion's allegiance to the cause, agreeing to help repair the Ark.
Axer, an ex-Decepticon, however, was also aware of the Autobot's quest to recover the Allspark, and attempted to dissuade the Junkion leader from this course of action. Nevertheless, Wreck-Gar, aiding Optimus Prime's side-quest to recover the Star Saber, agreed to lend him a salvaged ship from Junkion's orbit, so long as they returned it so that the Junkions could junk it.
It was only much later that this choice came back to bite him on the skidplate, as the Decepticons arrived and began to launch an all-out attack on the world of trash. Rallying his Junkions to defend their excavation sites, they were soon reinforced by the Autobots, who returned from deep space with the Blades of Time. As war raged across Junkion, the planet itself began to tear itself apart, due to the removal of the Requiem Blaster that had been hidden below the planetoid. Angry at the Autobots and Decepticons for destroying his home, Wreck-Gar nevertheless grudgingly ordered his bots to begin welding their world back together. This job was interrupted by the arrival of the Star Seekers, who forced the Junkions to upgrade their ship with a portable Space Bridge. Wreck-Gar and many of his fellow Junkions were forced aboard by Thundertron, and taken to places unknown as the pirates continued their hunt for Cybertronians.
Following the restoration of Cybertron from the Great War, Wreck-Gar was one of the many Autobots blacklisted by the new High Council for being a supporter of Optimus Prime.