Arnold believes in legendary creatures and is easily intimidated, making him a perfect minion for a Decepticon. He also has a flair for the dramatic.
Arnold once thought the Kospego was a myth, but one day in the woods, he encountered Thunderhoof and mistook the Decepticon for the creature. Thunderhoof ordered Arnold and some others to gather the items he needed to build a space bridge. He and two other minions visited the scrapyard near Crown City to obtain the last components needed, but were unable to purchase a generator. Despite this failure, Arnold and the other followers completed the space bridge, only to be confronted by two more legendary creatures called, "Sideswingo" and "Bumbeego." The two newcomers announced that they had come to punish the Kospego, and Arnold and the others fled. They later returned to the woods, hoping to find Sideswingo and Bumbeego for guidance and wisdom as they crept into the woods.
Out bird watching, Arnold and the group he was with were caught up in a fire started by Crazybolt. Fortunately Fire Marshal Denruss was nearby to dispense helpful information and the group took shelter, though as Arnold observed, things were getting hot quickly. An emergency vehicle soon arrived and carried Arnold and his group to safety on its trailer. Afterwards, Arnold thanked their rescuer.