After the Ark crashed into the Earth, Grimlock, Snarl and two others remained active and were reformatted to resemble dinosaurs, the planet's dominant lifeforms. Unfortunately the reformatting was a little too thorough and they were left acting like real dinosaurs as well. Rendered inactive by a meteorite strike, they lay dormant beneath what became modern-day Brazil until Grimlock and Snarl were inadvertently awoken by developers from a logging company. Optimus Prime , Jazz and Blaze travelled there to investigate but were ambushed by the Decepticons and Soundwave trapped the Dinobots in a plasma net . Unfortunately for him, the net caused a negative ion feedback which triggered their Transformer circuitry and restored their personalities along with their robot modes . Grimlock and Snarl sent the Decepticons packing but remained in Brazil to look for their missing comrades rather than return to the Ark with the Autobots. The Dinobots!
Grimlock helped to sniff out the "dinosaur transform static" that implicated Trypticon in the theft of world monuments. Later in the year, when Decepticon leader Galvatron had Cybertron infused with function-inverting anti-electrons, a dose of the particles gave Grimlock super-intelligence. For the first time Grimlock identified himself as "I, Grimlock". During a mission to Unicron 's disembodied head, where the Autobots were outmatched by the new Decepticon Terrorcons , Grimlock used components of Unicron's head to construct the Technobots to battle them. Combined as Computron, the Technobots felt they could not match the Terrorcons, until Grimlock transferred his super-intelligence into Computron, reverting to his old self and allowing the Technobots to claim victory.