Objectives will win a battle, but it is sheer ruthlessness that will win a war.
Grindor is one of Megatron's most loyal Decepticons from the Transformers franchise, acting as a genius tactician and heavy weapons specialist. Even for a thirty foot tall robot, Grindor is considered extremely dangerous and physically strong, appearing in Transformers: Revenge of the Fallen as a minor antagonist but having a more important role in the game based on the film.
Transformers: Revenge of the Fallen
Grindor makes his first appearance in the middle of the film when, in helicopter form, he soars over to human Sam Witwicky's car, that also contains his roommate and girlfriend. Picking up the vehicle and flying it over to a factory containing Starscream and a just revived Megatron, Grindor takes part in a large fire fight when the Autobots arrive before Megatron can interrogate Sam to find the location of the Sun Harvester, a powerful machine that the mysterious Fallen seeks. Grindor is viciously murdered by Optimus Prime later on in a large fight in the forest, as Prime stuck a pair of hooks in the Decepticon's face before pulling and ripping it clean in half.
Transformers: The Ride
End of the line, earth skunks!
~ Grindor as he pursues humans riding EVAC
Grindor appears in the theme park attraction found in various Universal Studios theme parks. He shows up early in the ride, as after Optimus tackles Megatron, Grindor flies in charging towards EVAC and the human riders, then transforms and tries to cut them open with his rotor blades in a train station. However, the riders are immediately saved by an incoming train that runs into Grindor and rips his right arm off (the arm with his anti-torque blade), as well as leaving him too injured to continue pursuit.
NOTE: The games are so much more different than the movie that it is considered a different canon.
That's right, Starscream. You don´t retreat, you simply advance backwards.
~ An example of Grindor's humor after Starscream refuses to accept his cowardice
Grindor serves the Decepticons the same way Ironhide serves the Autobots, the reckless heavy weapons expert. Though Grindor may be hot headed, he is a genius when it comes to battle and uses this to fight through Shanghai, Cario, and a West Coast United States town. After overseeing the Decepticons' "secret" mission to find the Allspark shard in Shanghai, Grindor was imprisoned at the docks only for Sideways to come save him. He then captured Sam Witwicky where Megatron (who was recently resurrected thanks to the shard) successfully interrogated him and got the location of the Sun Harvester, leading to a victory for the tyrannical Decepticons.
GIVE ME THE INSECT!
~ Grindor as he fights Bumblebee
Grindor has a minor role in the Autobot campaign and a mid-way boss where Bumblebee is forced to fight him with a boss. Grindor demands Bumblebee to give him the insect. Instead of that, Bumblebee gives the heavily armed Decepticon a shower of hand-fired missiles which weakens and finally kills him for good.
As aforementioned, there is a large controversy on whether Blackout and Grindor are one of the same. Though it has been confirmed that they are different despite being physically identical, there have still been several mistakes among the Transformers universe regarding their identities. Examples are that several toy products mix the two up. The writers of the film comics poke fun of this by having Ironhide retort, "Blackout. Grindor. They all look the same to me."
While he doesn't talk in the film, he does talk in the video game and the theme park attraction, Transformers: The Ride.
Grindor was voiced by Frank Welker in the film (even though it is just a few robotic grunts) but was voiced by Fred Tatascorie, who voiced all Beasts mode of the Beauty and the Beasts, The Grizz, Bane, the infected, and multiple incarnations of the Hulk.
Grindor transforms into a CH-53E Super Stallion.
Outside the movie series, Grindor is actually an Autobot Minicon featured in Transformers: Armada, as well as its continuous adaptations & outside incarnations. In can be inplied that he was named as such due to the name sounding villainous.
However, in the comics continuity of Transformers Animated, featured a homage to movie Grindor, under the name "Grinder", as there is already an Autobot named Grindor in the series.
Some fans believed that Grindor was originally meant to be Barricade but was dropped for unknown reasons.