In their first appearance in the Generation One series, the Dinobots were dispatched to Earth to discover what had happened to the missing Ark . They encountered the Decepticons, who would become the Insecticons , and both sides blasted each other into stasis lock. The Dinobots killed Octane and stole his ship, but they ran into trouble when the local Autobot forces believed them to be traitors and fired on them. Repaired by the Autobots, who were by now convinced of their intentions, they participated in the final assault on Shockwave, where Grimlock rescued Magnus and Optimus Prime.
According to the biography printed in the Transformers Collectors Club magazine, Slag and Sludge were part of Grimlock's band of Decepticon hunters on board the ship Graviton . When Grimlock left Ultra Magnus in charge to join Optimus Prime on Earth, Slag and Sludge departed the Graviton , not wanting to be under the command of Magnus. The two Dinobots went off on their own, and happened across Nightbeat. Nightbeat offered them a job as muscle, which they took because they figured Nightbeat has a nose for finding trouble, which they enjoy.