Grimlock is the name of several fictional characters in the Transformers universes.
Grimlock is among the strongest of the Transformers, possibly an equal to, or even superior of, Optimus Prime and Megatron in certain continuities. In Tyrannosaurus rex mode, his powerful jaws can snap virtually anything that comes between them - from steel cables to a Decepticon limb. He also can shoot an energy ray from his mouth. In robot mode, Grimlock wields an energo-sword, whose blade is sheathed in crackling energon and can slice a two-foot thick concrete wall in one slash. He also uses a double-barreled, self-propelled rocket launcher.
The discovery of fossilized dinosaur bones in a cavern in their volcano base set the Earthbound Autobots on the track to creating the Dinobots. Intrigued by the creatures, and with additional knowledge supplied by Spike, Wheeljack and Ratchet created three "Dinobots" - Grimlock, Slag and Sludge. It has not been explained why he or the other Dinobots were able to be fitted with personalities which can only be found on Cybertron from Vector Sigma. Apparently there is a difference between the brain and personalities in Transformers. Their brains are simple, yet still it is the personalities that make them sentient. It is evident that addition of personalities or "sparks" and its origin was after the fact, and was hoped that this inconsistency would be overlooked.
Unfortunately, their design specs proved to be a little too accurate to the creatures they were modeled on, as their primitive brains went out of control, and Grimlock almost destroyed Teletraan I, before the trio was stopped. Optimus Prime deemed them too dangerous to use again, and had them sealed back up in the cavern, but when the majority of the Autobot force was captured by the Decepticons, Wheeljack freed them to go to their rescue. Equipped with new devices that enhanced their brainpower to functional, yet still impaired, levels (resulting in slow thought processes and simple, clipped speech), the three Dinobots successfully rescued their Autobot comrades, and Optimus Prime admitted his error.
In his private thoughts, however, Grimlock considered Optimus Prime too weak to lead, seeking the position for himself. When Soundwave read his mind and learned of this animosity, Megatron was able to trick Grimlock and the Dinobots into switching sides, attacking and capturing Optimus Prime. To stop the turncoat Dinobots, two new ones were created: Snarl and Swoop. Ultimately, it was when Optimus Prime threw himself into harm's way to save Grimlock from an explosion that he accepted his mistake and rejoined the Autobots. In a rare form of modesty and humility, Grimlock emotionally apoligized to Prime, admitted his jealousy of the leader, and accepted fault for the battle. The two subsequently patched up their differences.
Although content for the moment to remain a soldier, rather than a leader, Grimlock still had trouble accepting orders, only agreeing to help stem the tide of natural disasters ravaging Earth due to Cybertron being pulled into its orbit when he realised he would die if he did not. Grimlock and the Dinobots were semi-regularly called into action when the Autobots were faced with challenges that required extra strength, such as the Sub-Atlantican invasion of Washington, D.C., or the Decepticons' control of the TORQ III supercomputer; with every piece of help he and his troops gave, Grimlock was never slow to add a scathing remark about the inabilities of the Autobots. That said, he was not unwilling to admit the failings of his own troops, either, and willingly took them to the time-displaced "Dinobot Island," where they trained in the wilderness and helped stop a Decepticon raid on the prehistoric paradise.
The final straw for Grimlock came when he and the Dinobots were injured in a Decepticon trap at an airfield. Enraged, Grimlock refused to take orders from Optimus Prime any more, and led the Dinobots away from the Ark. When the Autobots began to suffer from Cybertonium deficiency, Spike Witwicky and his girlfriend Carly attempted to persuade the Dinobots - who continued to function perfectly, as they had been built on Earth without Cybertonium - to steal some of the mineral from a Decepticon shipment coming in from Cybertron. Grimlock instead opted to lead the Dinobots to Cybertron itself, where they were captured by Shockwave and put to work in the Cybertonium mines, until Spike and Carly rescued them. Brought back to Earth, the Dinobots agreed to follow Prime's order again - until such time as Grimlock did not feel like it.
By the Earth year 2005, it seemed apparent that Grimlock had undergone some degree of a personality change, becoming more childish and petulant, rather than brutish and stubborn. Also of note, it seemed that, along with the other Dinobots, Grimlock remained in his Dinosaur mode almost exclusively, rarely ever changing back to his Robot form. Throughout 2006, he regularly participated in missions with his fellow Autobots rather than the other Dinobots, battling on the planets of Chaar, Goo, Dredd and Eurythma.
In episode 78, Madman's Paradise, Spike and Carly hosted a banquet for a visiting ambassador. Daniel got bored and wandered off. Grimlock followed him, and they fell into a lost chamber where Quintessons banished their criminals to other dimensions. They slipped through to the other-dimensional realm of Menonia, and were tricked into fighting on the Red Wizard's side, only to find out that he was the Quintesson criminal, who overthrew the Golden One. Ultra Magnus, Blaster, Eject, Rewind, Ramhorn, and Steeljaw followed, and using Blaster's amplification, they help the Golden One defeat the Red Wizard. With the help of Perceptor, the Autobots and Daniel are returned to Cybertron.
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.
Grimlock's greatest victory came when he and a large number of other Transformers with animal transformations were summoned to a world at the centre of the galaxy by the ex-assistant of the ancient genius, Primacron, creator of Unicron. The assistant had assembled these "Primitive" Transformers in the hope that their simple instincts could defeat Primacron's newest creation, Tornedron, but one by one they fell to him, with Grimlock apparently crushed under Trypticon. Grimlock survived, however, and followed Tornedron back to Primacron's lab. When Tornedron turned on his master, like his predecessor, Primacron's complicated plans and equations could not find a way to stop him; Grimlock, on the other hand, randomly flicked a switch which reversed Tornedron's energy polarity, undoing the damage he and done and dissipating. Dancing around over his successful saving of the universe, Grimlock decimated Primacron's lab, dubbing it the smartest thing he'd ever done.
After the animated series ended in the U.S. Grimlock appeared in animated form in the commercial for the Classic Pretenders.
In a comic story found in the Transformers DVD boxset for season 2, a special comic was donated by Darren Jamieson and Dylan Gibson that explored what happened when the Dinobots combined. Unleashed as a last ditch effort by Grimlock to stop an Autobot massacre, "The Beast" was a huge mindless combiner that destroyed warriors on both sides.
In the year 2011, the Decepticons invaded Cybertron in full force. Grimlock was deployed by Wreck-Gar to fend off the invaders. He was seen fighting alongside his fellow Dinobots as well as the Throttlebots against the invading Decepticons, however, they didn't fair too well against the Decepticon Headmasters, as they are all quickly put to sleep by Mindwipe's hypnosis attack. In the second episode, Grimlock was again in action, trying to protect Vector Sigma alongside with two fellow Dinobots and Jazz .
In 1984, when Shockwave was accidentally reactivated by an Autobot probe and took command of the Decepticons from Megatron, Autobot medic Ratchet entered into an uneasy alliance with the deposed Decepticon leader, agreeing to recover the Dinobots so that they might defeat Shockwave again. Ratchet pulled a double-cross, however, and had the Dinobots attack Megatron instead, resulting in a battle that ended with Megatron's disappearance.
Grimlock steadily grew more and more displeased with Optimus Prime's leadership, and eventually broke his Dinobots away from the main Autobot faction. After a prolonged period living in self-imposed exile, the news of Optimus Prime's death brought Grimlock back to the Autobots. After proving his worth by defeating the Decepticon Trypticon, Grimlock was elected leader of the Autobots.
It soon proved that absolute power corrupts absolutely. Grimlock developed into a tyrannical ruler who led the Autobots with an iron fist. His policy towards Earth and its inhabitants were vastly different from Optimus Prime's – instead of viewing them as objects of protection, Grimlock expressed a disdain for humanity, viewing them as an inferior species unworthy of their protection. Under Grimlock’s leadership, the Ark, was repaired and made space-worthy again.
In issue #32, titled "Used Autobots", Wheeljack completed work on his Geothermal Generator, which used the heat from the volcano the Ark had crashed in to generate energon cubes. Although Wheeljack thought this would impress Grimlock by reducing their dependence on human help, Grimlock seemed to think the Autobots should just take what they need from the humans.
Blaster and Goldbug could not endure Grimlock's leadership any more, and set out on their own, only to have Grimlock mark them as traitors. Blaster was hunted down by the Protectobots and later the Dinobots themselves, and placed under imprisonment and torture.
When the Autobot Headmasters and Targetmasters arrived from Nebulos, Grimlock refused to recognize the authority of Fortress Maximus and failed to establish an allegiance with his group. This proved to be the last straw for the Autobots under Grimlock's command, who collectively conspired to overthrow him, arranging for Blaster to challenge Grimlock for leadership. During their battle on the moon, the Decepticons took advantage of this weakness in the Autobot ranks and interrupted the duel with an all-out assault. With all Autobots now under attack from their mortal enemies, Grimlock and Blaster put their differences aside and fought alongside each other against the Decepticon horde. Subsequently, Fortress Maximus orchestrated the recreation of Optimus Prime as a Powermaster, and Grimlock stepped down as leader.
Grimlock and the Dinobots were destroyed during the battle against Starscream while the villain was super-powered by the Underbase.
Grimlock's body was seen among the deactivated Autobots Ratchet was doing his best to revive in Transformers #56, "Back from the Dead".
After a short time, Grimlock (along with Jazz and Bumblebee) was rebuilt by Ratchet as a Pretender. Ratchet shortly after was lost in a transport incident while taking out Megatron, and was thus unable to continue his work restoring other Autobots in stasis lock (Ratchet later returned, physically merged with Megatron). Grimlock swore to one day find a way to revive his Dinobots.
Under the leadership of Powermaster Optimus Prime, Grimlock proved to be a loyal and powerful Autobot, daring even to battle the Matrix-powered Decepticon Thunderwing during the Matrix Quest. However, he was still obsessed with quickly reviving the Dinobots, a goal which put him at odds with Optimus Prime, who advocated patience in the search for a way to rebuild the fallen Autobots. Grimlock finally lost patience, stole the bodies of the Dinobots and a shuttle from the Ark, and piloted it to the planet Hydrus Four, where scientists had developed a new fuel called nucleon. It was more powerful than energon and capable of bringing dead Transformers back to life, but it was unstable and could have unforeseen consequences. Grimlock was unwilling to subject his Dinobots to anything he would not go through himself, and thus decided to test the fuel on himself first. When no ill effects were apparent, he used it to revive the Dinobots, and brought enough back to revive the remaining fallen Autobots.
The Dinobots returned to Cybertron with the nucleon, and arrived in time for the battle with Unicron. Their arrival, and their reviving the fallen Autobots with Nucleon, was an important part of Transformer victory that day, but Optimus Prime once again lost his life, sacrificing himself to destroy Unicron, and once again naming Grimlock as his successor with his dying breath.
Before Grimlock could celebrate his new position, however, the Nucleon's effect on Transformers became apparent. Grimlock began to experience brief bursts of immobility, his joints locking, which reached a peak when he became completely paralyzed in Cybertron's wastelands while he and the Dinobots were under attack by monstrous creatures from beneath Cybertron's surface. Realizing that Grimlock had become trapped in a "chrysalis" stage, Prime's Powermaster partner, Hi-Q, tapped into and accelerated the process, completing Grimlock's evolution into a more powerful "Actionmaster" – but the enhanced power came with a price: Grimlock was now no longer able to transform into dinosaur mode.
At that point, Cybertron was believed to be dying as a result of the battle with Unicron, and the Autobots and Decepticons were co-operating to evacuate. However, the Decepticons had a hidden motive: to escape, and leave the Autobots marooned on the dying planet. Grimlock and the Dinobots were the only ones among the Autobots who saw through the Decepticons’ false pretense of peaceful co-existence and suspected the plan of mass betrayal. When the Decepticons sabotaged the Autobots' ships and fled the planet, Grimlock saved the Autobots. He revealed that he had captured Decepticon ships after a strike against them before the voyage to Earth, and had hidden them away. Thanks to those ships, the Autobots were able to flee Cybertron and follow the Decepticons to the planet Klo for a final showdown. Unfortunately Decepticon leader Bludgeon had discovered the Autobot homing beacon and laid a trap for them. Grimlock's stubbornness meant the Autobots walked right into it, decimating them. Grimlock was one of the few survivors, and when Optimus Prime returned, recreated by the Last Autobot, Grimlock participated in the rout of the Decepticons.
Set in and around the U.S. stories, Grimlock and the Dinobots were the stars of several stories while self-exiled from the other Autobots, including In The National Interest where they tried to help expose the Robo-Master hoax. When leader of the Autobots, Grimlock was involved in assisting Action Force battle Megatron in London and attempted to kill the Predacon Divebomb in order to silence embarrassing facts about Swoop's past.
Towards the end of the series, the UK comics began a break-away storyline that branched off from the continuity of the American stories, beginning with Grimlock's decision to once again break his Dinobots away from the main Autobot force. Tired of Prime's pacifistic approach to protecting Earth, Grimlock was joined by several older Autobots like Prowl and Wheeljack, who had just recently been reactivated, and longed for the older, simpler days. Under Grimlock's command, they formed the Earthforce, a pro-active Autobot group based in Canada who regularly battled the two Decepticon forces under the commands of Megatron and Shockwave.
Issue #279 of the Marvel U.K. Transformers comic featured a story called "Divide and Conquor!" where Soundwave lead the bulk of the Decepticon forces on Earth against the Autobot Earthforce headquarters while Starscream attacked an oil tanker. Sent into battle by Prowl, the Dinobots routed the main Decepticon forces while Springer lead the Autobot Survivors, Broadside, Inferno, Skids, and Carnivac to defeat Starscream.
There was no specific ending for the Earthforce crew, but the issue of nucleon was resolved in a one-shot text story contained in the final Transformers annual (a hardback book containing new material released each year). Of the Dinobots, only Slag retained the ability to transform, until the discovery of new nucleon allowed all the Transformers previously empowered by it to regain their transforming abilities. The place in continuity of this tale is hard to determine. It followed on from the events at the conclusion of the American series, yet cannot fit in with American continuity as it puts Megatron in a situation he cannot possibly be in.
With his transformation capabilities restored (the explanation for which was not offered in the American series), Grimlock was Optimus Prime's second in command in the so called Generation 2 series, aiding in the Autobots' war against the "second generation" of Cybertronians led by Jhiaxus. However, he remained as rebellious and aggressive as ever, though it proved to be a mixed blessing - at one point his urge to combat Jhiaxus's forces led him and his troops right into a trap, while at another time, his willingness to defy Optimus Prime's orders and launch an all-out attack saved Prime from certain death at the hands of Megatron. When the Autobots and Decepticons united against Jhiaxus and the threat of the Swarm - a destructive by-product of Transformer reproduction - Grimlock was the joint leader of the ground troops as Prime and Megatron fought on other fronts, and survived the brutal conflict.
Grimlock appeared in his blue Generation 2 form in the short lived UK. Generation 2 comic series.
Years later, writer Simon Furman offered an "unofficial" conclusion to the Generation 2 storyline with "Alignment", a text story available exclusively through the British Transformers convention, Transforce, in 2001 and 2002. In the story, Grimlock is killed while trying to distract the Leige Maximo.
Based on the Transformers Classics toy line, the Timelines 2007 story is set 15 years after the end of the Marvel Comics story (ignoring all events of the Marvel UK and Generation 2 comics).
When Bludgeon and his Decepticons were banished after the battle of Klo Grimlock refitted his Decepticon battleship, the Graviton, with weapons and recruited his several Dinobots and Autobots to hunt them down, including Ultra Magnus, Springer, Huffer, Elita One, Snarl, Terranotron and the Mini-Cons Swoop and Strongarm.
After getting word from Optimus Prime that Megatron was alive on Earth Grimlock left Ultra Magnus in charge of the Graviton and took a shuttle to Earth.
In "Crossing Over" when the Cybertronians Skyfall and Landquake arrive on Earth unexpectedly Megatron attempts to destroy them, but Optimus Prime and his Autobots are able to drive Megatron away and took Skyfall with them.
In "Games of Deception" the Graviton followed Bludgeon's agent Bugbite and several Decepticons to Earth where the Autobots joined up with Grimlock. After a brief encounter with the Decepticons the Graviton left with Grimlock joining them.
Classic Grimlock's biography was featured in 13 of the Transformers Collectors Club magazine.
Grimlock was an established, respected member of the Autobots (perhaps most remembered for his quote "Me Grimlock, badass!!!") at the time Autobot leader Sentinel Prime was killed, but was suitably unimpressed by the new leader, Optimus Prime, questioning his strength and resenting his opening decision to depart Cybertron and leave it for the Decepticons. Witnessing and aiding him in battle with Megatron deep beneath Cybertron, however, Grimlock came to respect Prime as time passed. When Prime and Megatron disappeared in an early test of the experimental spacebridge transport system, disarray struck the Autobot and Decepticon ranks and they splintered off into numerous smaller factions - Grimlock founded the Lightning Strike Coalition to fight the battles he considered the most important.
As the "Dark Ages" came to an end, Ultra Magnus reunified the various Autobot factions, with Grimlock becoming something of his right-hand man. Starscream's Predacon faction attacked an attempted peace treaty between the Autobots, the Decepticons and Ratbat's Ultracons. As Grimlock leapt to Ultra Magnus's defence, he apparently perished - naturally, we know he later returned to life, but unfortunately, due to Dreamwave's closure, this story was never resolved, and Grimlock's restoration to life was left unexplained.
What is known of the remainder of his time on Cybertron, however, is that he, Slag, Sludge, Snarl and Swoop formed a team known as the "Dynobots" (they are referred to as such in the first issue of "The Age of Wrath). The Dynobots remained on Cybertron when Optimus Prime left on The Ark, pursued by Megatron. When Optimus Prime and Megatron's troops vanished four million years ago, they pursued the Decepticons known as the Insecticons, who had set off in search of the missing leaders. The two teams battled on prehistoric Earth, and the battle ended with both sides trapped in stasis. The eventual awakening of Prime and Megatron's forces in 1984 was followed by the Autobots' discovery and reactivation of the Dynobots, now rechristened the "Dinobots" for their new dinosaur alternate modes.
When the Transformers were all believed destroyed in the explosion of the ship that was taking them back to Cybertron, several of them, including Grimlock, were recovered by a rogue military faction and reprogrammed so that they could be operating as killing machines. Bumblebee, Frenzy, Grimlock, Laserbeak, Prowl, Ravage, Soundwave and Starscream were forced to attack the Smitco oil refinery in the Arctic to display their power for sale to the highest bidder (Transformer: Generation One #2).
When Megatron liberated himself and several others from this control, Grimlock, tired of risking his life for the humans, joined him, ripping off his insignia and joining in the Decepticon attack on San Francisco, during which he was dispatched from behind by Trailbreaker. Left behind by the fleeing Decepticons, he subsequently located and liberated the other Dinobots, and headed for Cybertron. In the four-million-year interim, the planet had been unified by Shockwave for his own sinister ends, but once there, Grimlock led an assault on Iacon, providing enough chaos and unrest for Optimus Prime's Autobot underground to overthrow Shockwave's rule of Cybertron. Grimlock successfully hauled Optimus Prime and Ultra Magnus to safety when Shockwave's citadel exploded.
Grimlock returned in the third series as a main character. Grimlock, Arcee, Bumblebee and Perceptor were sent to Earth to aid G.I. Joe in removing the influence of Cybertronian technology on the planet. When Cobra attacked the base, the Autobots helped repel the Cobra Battle Android Trooper armies. This was simply a distraction, however, to allow Cobra Commander access to the real prize - Serpent O.R., a technorganic android created from the DNA of many great warleaders and parts from Megatron. Predictably the Megatron aspects took control and Serpent O.R. escaped, taking over the G.I. Joe battlesuits and forcing Grimlock and the other Autobots to battle them while he made his escape. The Autobots and Joes pursued him to Cybertron, where they were captured by Serpentor, the Predacons, the Seacons and the Stunticons. While Serpentor captured Optimus Prime, Snake-Eyes led a jailbreak, with Grimlock flattening Rampage in the process. He would then form part of the combined Autobot/G.I. Joe strike force to rescue Optimus Prime, at one point ripping a Decepticon prisoner's arm off to gain Prime's location. At the end, after Serpentor's defeat and Prime's rescue, Grimlock admitted he was wrong about the Joes, and that they were great heroes, warriors and friends.
There is a notable disparity in Grimlock's speech patterns between the second and third series. In the second series he is seen to speak normally, referring to himself as "I". However in the third series he speaks in his more normal "Me Grimlock" speech.
In the Transformers Spotlight issue on Shockwave, Grimlock and the 'Dynobots' (sporting Cybertronian designs much like their War Within designs) appear in a story that partially pays homage to their Marvel G1 origin. Seeking payback for a humiliating defeat by Shockwave, Grimlock pursued him to prehistoric Earth (which Shockwave was seeding with Energon). In order to protect themselves against Energon surges, the Dynobots required alternate modes covered by a layer of synthetic flesh. Refusing to pick dying and thus weak Ice Age mammals for an alternate form, Grimlock chose to utilise more ferocious dinosaruian beast modes which were much more impressive. The Dynobots got the initial jump on Shockwave, as their attack was too illogical for him to understand, but he quickly recovered and dispatched the entire team, destroying their synthetic skins and sending them into stasis lock. Grimlock got the final laugh, as the Dynobot ship fired a pre-programmed blast into the surrounding volcanoes to unleash a flow of lava that engulfs all six Transformers until they were uncovered by human paleontologists in 2006.
Following this Skywatch, a government agency who knew about Transformers, took over the site. Later, following escalating Transformer activity on Earth (as seen in The Transformers: Devastation), and losing control of their other captive Transformers Ravage and Laserbeak, Skywatch reactivated Grimlock as a response. The reawakening was sabotaged by the Machination, and Grimlock escaped. He met Scorponok, who proposed an alliance as they were both now fugitives. Grimlock refused, but lost the subsequent battle, teleporting himself to the Dynobot ship. Vowing to bring down Scorponok, he was unaware the Machination were manipulating Skywatch into reactivating the other Dynobots, with the aim of having them dispose of Grimlock (Spotlight Grimlock).
He appears among the Maximals on the cover of the first issue of the sequel story Beast Wars: The Ascending. In the beginning of Beast Wars The Ascending Razorbeast speaks to Prowl and Wolfang about how he feels there is no rescue mission coming for them from Cybertron as Grimlock hunts in the nearby woods. In Beast Wars: The Ascending #4 Grimlock was among the Maximals and Predacons returned to Cybertron to battle Shokaract.Duncan
The Autobots returning to Cybertron along with Blackarachnia and Silverbolt were then abducted via teleportation beams and taken to Unicron. Tap-Out, Transformers: Armada Megatron, Brawn, War Within Grimlock and Snarl were also abducted from various timelines (Transformers: Universe #1).
War Within Grimlock, Armada Megatron and Universe Optimus Primal are each transported to the Unicron world, where they eventually team up and fight Striker and Reptilion. Note, there is a small continuity error in that this story ends with Grimlock, Megatron and Primal standing over Reptilion, but issue #2 of the comic starts with them standing over Striker (2003 Botcon Voice Actor Play).
After the events of the Botcon 2003 voice actor play, Optimus Primal is able to use his spark telepathy to free Striker from Unicron's influence. Optimus Primal, Megatron and Grimlock help break free the slaves from various timelines which are held there and gets them to Cybertron (Transformers: Universe #2).
The first completely different character to bear the name of Grimlock was one inhabiting the alternate universe of the 2001 Transformers toyline, Transformers: Robots in Disguise. Grimlock is a 1:60 scale toy.
Grimlock (originally named Build Hurricane in the original Japanese version of the series, Car Robots) was a co-leader of the Autobot Build Team, able to transform into a steam shovel. Despite his harsh appearance, Grimlock is a seasoned, upbeat warrior. He judges any situation in a composed, calm manner, and dispenses accurate advice based on his many past experiences in battle to others, particularly his leader, Wedge. He can combine with his fellow Build Team members to create Landfill, able to form either a leg or a pair of arms.
Play Synopsis: Rhinox has built a device to deflect Unicron's attempts to pull victims from other dimensions with his tractor beam. The Autobots deflect two attempts and the victims end up on a frozen planetoid instead of with Unicron. Maximals Rattrap and Silverbolt and the Predacon Waspinator are sent to help the victims, but Reptilion, Sunstorm, Ruination and Universe Perceptor are sent to get them for Unicron. As a side effect of the device Rhinox built, a vortex opens which sucks in an Autobot shuttle from the past piloted by Bumblebee, Tracks and Cosmos. Thrust attacks the Maximal ship, but they are saved by being transported to the Autobot shuttle. The Autobots and Maximals then go to the planet where they save the victims from the Decepticons. On the planet are two groups of Autobots. One is from the Robots in Disguise story, with Landfill (Walmart recolor), Universe Side Burn and Universe Prowl. The other is from another parallel world with Spy Changer Optimus Prime, Ultra Magnus, Prowl and Ironhide. They all fight off the Decepticons. The Autobot shuttle is sent back to its own time.
In "Blast From the Past" the Autobots visit a dinosaur-themed amusement park where animatronic dinosaurs are on display, but Bulkhead accidentally breaks them. Professor Sumdac and Megatron rebuild the animatronic dinosaurs as technological wonders named the Dinobots, who go on a rampage under the Deception's influence until the attacks powered Sari's AllSpark key effecting Bumblebee and Ratchet's Electromagnetic blast against the Dinobots by making them conscious. Finding a way to control them, Megatron told Grimlock to attack the city by telling the Dinobots they are "fossil feeders" due to the way Earth vehicles are powered and that the Autobots are even worse. The Dinobots are lured away by the Autobots, with Prowl secretly placing them at the later named Dinobot Island in hopes that they'll live in peace. However, while expressing his rage at two birds defecating on him, Grimlock accidentally transforms to robot mode and finds his new form to his liking.
The episode "Survial of the Fittest" marks his, as well as the rest of the Dinobots, official side change when they help defeat Meltdown, Cyrus "The Colossus" Rhodes, and Meltdown's experiments.
In "Megatron Rising" Pt. 1, Optimus Prime, Prowl, and Bulkhead try to get the Dinobots to help them fight the Decepticons, but they refused saying that robots are their enemies. Upon them being told that they are robots too, Grimlock and the other two Dinobots end up fighting each other.
In "The Elite Guard," Optimus Prime leads Ultra Magnus and Sentinel Prime to the downed ship on Dinobot Island when they run into Grimlock and the Dinobots. Despite Optimus' warnings, Sentinel Prime charged them and got defeated. Ultra Magnus repelled them with the lightning he summoned with his hammer.
In "A Fistful of Energon", Prowl and Bulkhead are sent to the island where the Dinobots are, once again, to investigate the reports of a rampage. Soon enough, Grimlock heads right towards Prowl and Bulkhead, thinking something has made him hostile, but later discovering something is wedged between his foot, and yank it out.
Later, under Blackarachnia's seduction, Grimlock returns in the episode "Black Friday" to break out Meltdown. Out of the Dinobots, Grimlock had the most love for Blackarachina, refusing to accept that she's using him when she departs, leaving him heartbroken.
According to the Tech Specs Grimlock was created as an experiment in artificial intelligence by the Decepticons which became too violent and Megatron shut him down. Optimus Prime then liberated Grimlock and let him work for the Autobots.
Grimlock appeared as a member of Optimus Prime's forces in the "Shattered Glass" story.
Grimlock appeared in the fiction "Dungeons & Dinobots", printed in the Transformers Collectors Club magazine issue #22. Huffer attempted to capture Grimlock, but Grimlock chased him away while following a voice into the depths of Cybertron.