Grimlock isn't much for subtlety. Well, he does like to sneak up on the panicked Decepticons that are desperately fleeing the attacks of his aerial partner Swoop, but soon as they get in range of tooth and claw, he becomes a storm of violence, ripping into them mercilessly. Even though he is equipped with some heavy built-in firepower, he'd much rather take the up-close and personal approach to battle, especially bringing out the "big guns" by combining with Swoop to form the monstrous Mega-Dinobot.
- Grimlock & Swoop (Mega, 2005)
- Grimlock transforms into a robotic Tyrannosaurus rex. He can also form the upper body of the combined robot Mega-Dinobot. He was available only in a Mega-class multi-pack with Swoop.
- The Grimlock/Swoop set was originally intended to be released in the Universe line as the original Generation One incarnations. However, a variety of factors shuffled the set into Energon and new-character-dom.
- This set was not "mech-designed" or engineered by Takara employees, a rarity for normal-series Transformers toys.
- Grimlock's online bio at the then-Energon-themed Hasbro Transformers website described him as being "armed to the nines", despite a total absence of weapons and (due to his small fist holes) the inability even to use the Energon weapons available in the line.