Bumper is an Autobot trainee. He usually looks panicky, and he never looks like a Movie design.
Titan Magazine comics
Bumper was part of a training group-turned-strike force led by Ironhide against a Decepticon prison facility. While Skyblast, Signal Flare and Strongarm drew the fortress' fire, Bumper and Slipstream followed Ironhide in on an attack run. They blasted their way in, finding the base deserted except for a single Swindle, and rescued their imprisoned comrade.