In Transformers, he is the Leader of the Dinobots. He is one of the most powerful Autobots.

There are two distinct interpretations of Grimlock:

In the cartoon series, he is a strong but dumb "comedy" character.

In the comics, and especially in Simon Furman's version of him, he is a born warrior and hardman, who has a very different approach to leadership to Optimus Prime. He believes that Prime's compassion prevents the Autobots from defeating the Decepticons. He looks down on those he considers inferior, but is fearless in battle.
Although arrogant and stubborn, Grimlock is a highly effective leader. He is an anti-hero, a cross between Wolverine and Leonidas.
"Optimus Prime is too soft, if Grimlock were our leader, we could have won this war long ago!"

"Me Grimlock, Badass!"
by GaryUK August 2, 2007
Get the Grimlock mug.
Big ass robot who turns into a bigger fucking g robot dinosaur

Basically a badass, and don't let his intelligence fool you, he has an IQ level of 10 million
Grimlock is smart
by TheElite49 October 9, 2019
Get the Grimlock mug.
1) In Advanced Dungeons and Dragons, a Grimlock is a large and powerful grey-skinned humanoid, looking rather like a grey orc. Grimlocks are primitive, but also vicious and aggressive.

2) In Transformers, Grimlock is the leader of the Dinobots. He transforms into a Tyrannosaurus Rex. A staple character throughout the entire run of the TV series and the comics, Grimlock even went through three different toy versions in Generation 1.
Me Grimlock! Me king! Me kick your butt!
by Andy July 23, 2004
Get the Grimlock mug.
kick ass dinobot from the 80s classic kids TV program Transformers
GRIMLOCK: Me Grimlock not "nice dino". Me bash brains!
by Carnophage December 16, 2004
Get the Grimlock mug.
The act of a grenade bouncing back towards the person who threw it. Grimlock2 is notorious for this act.
Grimlock2 cooked his grenade only to have it bounce off a low ceiling back towards him, to which he exclaimed, "Shit! I grimlocked it!"
by ThatsRightCOW June 22, 2009
Get the Grimlock mug.
1) Leader of the Dinobots.

2) Expletive used for when seeing something gross, or 'grim'.
Person 1: "Ouch, that bum over there just shot up in the vein between his fingers"

Person 2) "Ergh, grimlock"
by goldenbrown August 23, 2008
Get the Grimlock mug.