Reptilion was once a noted scholar, his intellect on par with Perceptor's and his skills in propulsion technology without peer. Then, on a routine exploratory mission, he was abducted by Unicron, whose decimated body was trapped between dimensions. Reptilion was forced to work on the Chaos-Bringer's ruined planetary drive, a task to which he applied all the brilliance and dedication for which he had been chosen. He specifically pursued more effecient methods of space travel, especially warp gate technology. His thralldom has been long, and in fact he is Unicron's longest-serving general.