Grimlock is a member of Bumblebee's team on Earth, and a wild card among the Autobots. Huge and powerful, he's also headstrong and reckless. He transforms into a robotic Tyrannosaurus Rex, a powerful form that's essentially a wrecking ball on two legs. He's what you call a 'bot of action; he has little patience for complicated strategies and prefers to think of plans on the fly. Of course, his usual "plan" starts and stops at "punch it". He's not a particularly skilled fighter, eschewing guns and blasters in favor of his own fists, but when you're a heavy-hitting Dinobot, sheer force is often all you need to get the job done. Grimlock’s fights involve a lot of collateral damage, and the big guy's not the brightest 'bot around. Still, Bumblebee recognizes that the advantages of having a robotic dinosaur on their side outweigh the downsides, and Grimlock is always excited at the prospect of smashing up some of his monstrous jailmates from his days aboard the Alchemor.
Grimlock was one of the criminals in stasis on the prison ship Alchemor, who was stuck in his stasis pod when the ship had crashed on Earth. Though its unclear as to whether he actually was a criminal.
In Pilot (Part 1), Grimlock heard a commotion outside of his stasis pod and managed to break his head through his stasis pod to see Fixit and Russell outside his pod. Grimlock wanted to fight, but Fixit fiercely told him to go back in his cell by zapping him. Grimlock immediately recognized Underbite, due to Underbite's reputation on devouring a city on Cybertron and the smell was the reason Grimlock knew him. Underbite was raged by this and managed to free Grimlock from his stasis pod when he was tossing Grimlock around in his mouth.
In Pilot (Part 2), Grimlock was freed and he transformed into his dino mode to see Bumblebee, Strongarm and Sideswipe before fighting Underbite. After a few rounds of facing Underbite, Grimlock was tossed by Underbite and was unconsciousness for a moment. When Grimlock woke up, he asked Bumblebee and his team what happened. Strongarm told Grimlock that Underbite tossed him like a lobbing ball. Grimlock was surprised to know that nobody got hurt. Grimlock went with Bumblebee, Strongarm, and Denny in his pick up truck to stop Underbite from reaching Crown city. They managed to weaken Underbite and block the bridge until Sideswipe and Russell arrived with bait to lure Underbite away. It worked, and the team managed to get Underbite near to a cliff. As they were trying to push Underbite into the bottom of the cliff, Grimlock states it was awesome doing this process but it failed as Underbite was able to eat some of the bait to recharge his strength and pushed everyone aside. When Underbite was about to crush Denny in his pick up truck, Optimus Prime grabbed on Underbite's shoulder and tossed him in the cliff to save Denny.
After Optimus gave a speech to Bee and his team, he disappeared from their optics. After Grimlock witnessed Underbite being put into stasis, he wondered if Bumblebee would do the same with him. Strongarm was about to state a protocol about prisoners must remain in their pods, Bumblebee puts Grimlock on probation. Grimlock was excited by this as he hugged Strongarm around and singing "I'm on probation." As Strongarm and Sideswipe argue, Grimlock grabbed on their shoulders and started singing "I'm on probation."
In Trust Exercises, Grimlock and Bumblebee was doing their trust exercise where Grimlock carried Bumblebee in front of Sideswipe and Strongarm. When the team returned to base, Fixit informed them about a sharkticon attacking an oil tanker. Bumblebee took Grimlock with him to capture the sharkticon but Grimlock jumped on the sharkticon only to be knocked off and remained stuck on the bottom of the ocean. The pair failed to capture Hammerstrike and Grimlock was able to get to shore to get to the base. Grimlock apologized to Bumblebee about messing up and Bumblebee told him there are steps to follow. Bumblebee and Grimlock managed to find Hammerstrike where they hold him up against a wall but Hammerstrike was able to break a pipe that was filled with oil, thus leaving the room slippery for both Bumblebee and Grimlock. Hammerstrike used it to his advantage but Grimlock had an idea of trapping the sharkticon in a barrel. Bumblebee pushed Hammerstrike into the barrel Grimlock was holding and Grimlock quickly shuts the barrel. Grimlock seemed disappointed that he did not get to punch Hammerstrike but he was able to punch the barrel Hammerstrike was in, which made him a little happy. Back at the base, after Sideswipe and Strongarm explained about encountering Steeljaw, Grimlock went to put away Hammerstrike.
In More than Meets the Eye, Grimlock helped the team capture Bisk where they took some time and effort in bringing this con down. Grimlock used his cannonball attack on Bisk and Bisk was unconscious. Back at the base, Grimlock was thrilled as he talked about capturing Bisk. Later on, Grimlock assisted the team in hunting Chop Shop but failed to capture him as Chop Shop stunned Grimlock, Sideswipe, Bumblebee and Strongarm. Grimlock remained at base with Russell while the team took Denny Clay and Fixit on the mission to capture Chop Shop. Hank arrived at the scrapyard where Grimlock stayed motionless like a statue and stood beside Russell when she came. Hank admired the dinosaur statue and Grimlock immediately liked her. Grimlock tried to cheer up Russell and mentioned that Hank needs him at the football game. Russell manages to kick a football out of his rage, which impressed both Grimlock and Russell himself. Grimlock was shocked to learn Fixit punched around Chop Shop and helped capture him. Grimlock was impressed at Fixit and stated that they had to go see Russell play football. The Autobots celebrated when Russell scored on his team.
In W.W.O.D.?, Grimlock laughed at Strongarm's jump on Sideswipe after Sideswipe had given her a wet willy in her audio receptors. When the team split up to search the Crown City museum for a Decepticon, Grimlock briefly tangled with Terrashock in a planetarium, but came off second. Bumblebee eventually came up with a way to hunt the Decepticon on his own terms, which Grimlock enjoyed immensely. The team captured Terrashock and made their way off into the sunset.
In As the Kospego Commands!, Grimlock and Sideswipe were in charge of protecting the dam's generator. However, Grimlock ended up being left on guard by himself when Sideswipe said he was going to "scout the perimeter", which meant he was going to listen to music. Grimlock was trounced by the Decepticon as Bumblebee, Sideswipe, and Strongarm went to him. Grimlock was knocked silly, suddenly believing he could fly, and had to be helped back to the scrapyard by Strongarm.
In Collect 'Em All, Grimlock's attempts to disguise his beast mode as a truck were less than successful, resulting in him being left at the scrapyard when Bee and the others were hunting for Filch near Crown City. It later turned out they needed him after all, but only to hold up a bridge. He was able to hold the bridge for a short period of time since it was starting to collapse on him, but he was saved when Bumblebee arrived with a support beam for the bridge. Grimlock went back to the scrapyard with the others as they sneak into the scrapyard to avoid being detected by Larry LaRue.
In True Colors, a cyber-tick named Minitron took control of Grimlock, forcing him to fight his friends and then make off with Underbite's stasis pod. The other Autobots followed him to Crown River Dam where Minitron met with Steeljaw. Although Minitron tried to goad the Autobots into attacking one another, Grimlock managed to pin him down and subdue him. As a reward, Grimlock was formally inducted into the Autobot ranks.
In Rumble in the Jungle, while Bumblebee and Strongarm were away on a mission, Sideswipe and Grimlock got to be spectators for a feud between Fixit and Denny. They worked with Russell to settle the feud between their friends and fist bumped with Russell when their plan worked.
In Can You Dig It?, after Ped raided the Bots' energon supply, the others left Grimlock to guard what was left, and went to hunt the Decepticon. Later as they attempted to trap Ped, Grimlock himself became trapped at the bottom of a pit Ped dug until Denny came back with more cables for the magnet carrier.
In Adventures in Bumblebee-Sitting!, after a run-in with Quillfire left Bumblebee with reduced maturity, Strongarm and Grimlock went to hunt the Decepticon in a carnival, only to be joined by their leader. Grimlock got used as a steed and experienced a carnival ride before Quillfire was captured. When Bumblebee was back to normal after waking to find himself chained to a pole, Grimlock told him that Strongarm did a good job filling in for him back at the scrapyard.
In Hunting Season, when Drift and Fracture came to Earth to collect the bounty on Bumblebee, Grimlock was captured by the Decepticon to use as a ransom along with the other Autobots. Grimlock and the others were freed when Jetstorm and Slipstream hijacked Fracture's ship.
In Out of Focus, as Bumblebee's team pursued Malodor and three other Skunkticons, Grimlock found himself repeatedly sprayed with their debilitating toxin, and was briefly taken hostage by the Decepticon quartet. He helped capture the Skunkticons, but was again sprayed with toxin in the process. Bumblebee promised to say his message again to Grimlock when the toxin wore off.
In Sideways, the Autobots encountered the Decepticon Clampdown, whom Grimlock found extremely creepy. The Autobots were led to tangle with Steeljaw's gang. Grimlock once again battled Underbite, and managed to gain the upper hand by force-feeding the Chompazoid plastic. The Decepticons were subdued and briefly captured until Steeljaw slipped his cuffs and caused a distraction. While Grimlock and the other Autobots were preoccupied with a runaway garbage barge, the Decepticons escaped.
In Even Robots Have Nightmares, Grimlock joined Russel for a night of scary movies, and unsuccessfully tried to frighten the young human, who claimed not to be afraid of anything. Along with the rest of the Autobots, he later traveled to a local cave system in search of Nightstrike. The Decepticon got the drop on the team and incapacitated all of them with his fear-inducing scream, forcing Grimlock to have nightmares about kittens. Although the Autobots escaped and managed to capture Nightstrike, Grimlock was still jumpy in spite of his claims to the contrary, and quickly fled at the sight of a local stray cat.
In Some Body, Any Body, Grimlock was later dispatched to the Crown City subway system to track down another Decepticon contact, although Strongarm was less than enthused about having to tow the Dinobot all the way there. By the time they had arrived, they discovered that the demented scientist Vertebreak, had stolen Sideswipe's body, and was all too eager to try it out on the Autobots. Strongarm fought Vertebreak, but Grimlock was held up by passing trains. The Autobots eventually manage to take in Vertebreak, but Grimlock was too slow to outrun the oncoming train, forcing the other wheeled Autobots to carry him and the Decepticon to safety. The Autobots managed to subdue the Decepticon with the aid from Sideswipe's advice and Grimlock was there to witness Strongarm using Fixit to repair Sideswipe's head back to his body. Grimlock added a burn joke when Sideswipe pulled a prank on Strongarm. Grimlock carried Vertebreak back to base and also managed to get ahead of Sideswipe since he could not transform into his vehicle mode.
In One of Our Mini-Cons Is Missing, Russell explained to Grimlock about the notion of "paying it forward", which confused Grimlock. With the help of the newly-arrived Drift and his Mini-Cons, Grimlock helped to recapture a tank that had been commandeered by an escaped Quillfire and Springload and deliberately made sure not to catch either of the falling Decepticons.
In Deep Trouble, during a training exercise, Grimlock was injured by a falling piece of debris. Feeling that he was "the muscle" of the team and couldn't let his teammates down, Grimlock did his best to hide the injury from Bumblebee. This would eventually have repercussions when the team went underwater in pursuit of Octopunch, who had broken into an abandoned Cybertronian spaceship. The Dinobot steadily grew weaker and less focused, unable to fight off the ship's various security measures. Eventually, Grimlock told Bumblebee the truth about the injury. He was aided by Bee and they both managed to take down Octopunch. Grimlock smashed the control with his tail before the ship started its self-destruct protocols. As the Autobots were escaping back to base, Sideswipe and Strongarm took carrying Octopunch off Grimlock's hands as they old their teammate he should take a break and they are a team. Upon successfully returning to base, Grimlock was about to be patched up by Fixit when Strongarm suddenly had the strange urge to go on patrol.
In The Champ, Grimlock's increasingly brazen shows of strength did not have the desired effect; one stunt wound up almost injuring Russell. When the other Autobots headed into Crown City in pursuit of Groundpounder and Headlock, Grimlock's dinosaur alternate mode meant that he couldn't tag along. When the GroundBridge malfunctioned, however, he got his chance. With a roll-cage welded to his back, Grimlock posed as "Dino-Bash", a human-built robot piloted by Denny, and challenged Groundpounder in a demolition derby at the Crown City Rumbledome. Groundpounder was eager to tangle with a real Dinobot, and initially gained the upper hand. Grimlock, with Fixit's assistance, was able to nail Groundpounder with his signature cannonball move but not without almost bringing down the entire arena. The Autobots celebrated as Grimlock and Fixit were given the winner's trophy.
In The Trouble with Fixit, after Fixit reverted to his sentry programming, Grimlock was menaced by the various security measures around the scrapyard. Things were compounded by the return of Chop Shop, although Grimlock helped to bring in the Decepticon thief once again. Grimlock was also there to help his friends capture Chop Shop and fix Fixit. He was glad when Fixit went back to his normal state.
In Lockout, Grimlock joined the gang to investigate a Decepticon signal that belonged to Kickback. After returning to base, they discovered that Steeljaw had broken in and taken Fixit and the humans hostage. The Autobots attempted to get in the scrapyard several times to avoid being hurt by the auditory and body damaging program Steeljaw had placed. Grimlock and the other Autobots made noise to distract the Decepticons outside of the base. When the Autobots were able to regain control, they fought Steeljaw's pack. In the ensuing fight, Grimlock easily trounced Clampdown with a few well-placed tail smacks. Grimlock backed up Drift in his fight with Fracture and Bumblebee with Steeljaw. Grimlock helped chase Steeljaw and his gang out of the scrapyard.
In Similarly Different, Grimlock eventually grew bored with his routine duties, and yearned for the days when he could simply smash whatever he wanted to. While on patrol he encountered Scowl, another Dinobot. The duo happily destroyed an old demolition site, but Grimlock realized that he had to do the right thing and arrest Scowl. Scowl managed to win him over and Grimlock let him walk free, on the condition that he never harm a human. Unfortunately for Grimlock, Scowl was actually one of Thunderhoof's old goons, and the Autobots rolled out to bring him in. Grimlock had to fight against a vengeful Scowl at a train station, where he helped redirect an oncoming train, and later at a spa, where he finally managed to overcome the other Dinobot with the help of a stone sculpture. Grimlock was saddened by the outcome of the fight, and mused that Scowl had never intended to change his violent ways. Bumblebee cheered Grimlock up when he was surprised by his teammate's awareness. They returned to the scrapyard with the incapacitated Scowl to find that Denny, Russell, and Fixit were dancing. Grimlock questioned on what the team missed.
In The Buzz on Windblade, the Autobots discovered Windblade, a charismatic 'bot who had been sent to Earth by Primus eons ago. With their ranks temporarily bolstered, Grimlock helped the team go after Zizza, discovering her hiding spot at a nearby airport and then distracting her mind-controlled human pilots. When Zizza was captured, Grimlock informed the team that he bent the airplanes back to normal.
In Ghosts and Impostors, Grimlock began feeling homesick for Cybertron and the Acid Wastes. Bumblebee tried to cheer up the team by taking them to Edmondville, where they pranked a visiting human tourist group and discovered the Decepticon Shifter Pseudo. Grimlock fell for one of Pseudo's tricks by punching a rolling crate full of explosives and left ashes on both Bumblebee and himself. Although Pseudo temporarily masqueraded as Grimlock in the team's search in the mines, the team were able to spot the imposter and recapture him. Grimlock and the others observed the sunset together.
In Battlegrounds, Part 1, after Strongarm and Sideswipe were kidnapped by Decepticons, Grimlock joined the remaining Autobots and Windblade for a raid on their hideout. When the Decepticons absconded to the Crown City Colossus with their hostages, Grimlock took the direct route by travelling underwater, although he was barred from destroying the portal by Clampdown.
In Battlegrounds, Part 2, with Megatronus on the loose, Grimlock teamed up with his allies, including a reborn Optimus Prime, against Megatronus and the other Decepticons. Grimlock, Bumblebee, Strongarm, Optimus, and Sideswipe managed to distract Megatronus long enough for the other Autobots to bring down part of the statue's arm on their foe which enabled Bumblebee, Strongarm, and Sideswipe to link their Decepticon Hunters to blast Megatronus where he stood. In the aftermath, Steeljaw's pack (except for Steeljaw) were placed in stasis pods and Grimlock opted to stay on Earth with the rest of the team.
in Overloaded, Part 1, Grimlock was relaxed as Russell buffs his right side in his Dino-mode. However, he was alarmed when Micronus projected a vision on his right flank. Following a GroundBridge explosion, Grimlock helped, very badly, to clear up and along with Bumblebee and Strongarm as he claimed to Fixit it was his "gently". Grimlock attempted to fight Overload but was defeated by the Decepticon when the Decepticon had arrived at the scrapyard. The team noticed Bumblebee's strange behavior towards Overload's sudden appearance.
In Overloaded, Part 2, after tracking Overload to a parking lot, the team split up with Grimlock and Strongarm trying to track the Cyclone Mini-Cons. They soon realized they'd actually been tracking humans, however Grimlock came up with a plan that let them maintain their cover. They caught up with Bumblebee in time for Grimlock to witness Bumblebee's punch to Overload's face which he claimed it to be "Grimlockian". Grimlock helped carried Overload back to base.
In Metal Meltdown, despite Strongarm's coaching, Grimlock was unable to establish the same level of teamwork with her that she'd had with Sideswipe, leading to them bungling the capture of Saberhorn. They eventually managed to successfully work together at the steel mill, however Grimlock ended up throwing Saberhorn through a wall and inadvertently allowing the Decepticon to escape. Strongarm assured him about the mistakes she made with Sideswipe and promises they will capture Saberhorn. Back at the scrapyard, Fixit disturbingly reveals to them about Saberhorn actually being a prisoner on the Alchemor.
In Suspended, Grimlock took part in the pursuit of Crazybolt and Slicedice, during which he was able to help save some motorists accidentally endangered by Strongarm's mistake. Grimlock was involved with Bumblebee, Fixit, and Denny's plan as they attempted to make Strongarm get out of her demoralized state which proved unsuccessful. Later Grimlock helped Bumblebee try to deal with a fire caused by the two Cons, but they ended up requiring Strongarm's help to rescue some humans. Strongarm aided her friends and felt a lot better. Much to Grimlock, Fixit, and Denny's warning about watching the gnomes as Strongarm gained her Decepticon Hunter back, she did not harm them and stated she was professional as she shares a laugh with them.
In Brainpower, feeling that the other Autobots didn't rate his intelligence after capturing Torpor, Grimlock got Fixit's help him in trying to pass the police academy entrance exam. However a mishap resulted in Grimlock downloading the entire content of a Cybertronian data cylinder into his brain. Though it greatly increased his intelligence, it also meant the eventual degradation of his neural pathways and as he joined in the hunt for Simacore, Grimlock soon found his new knowledge left him unable to effectively fight the Decepticon scientist. After Grimlock grabbed the circuit board from Simacore and found shelter in a nearby room from Simacore and his Mini-Cons, Denny, Russell, and Fixit arrived to aid Grimlock in his dire situation to save Bumblebee and Strongarm from being blasted by the particle accelerator. Fixit was able to reverse the process, draining Grimlock's intelligence away just in time. Though Grimlock remained unable to move around from the process, he challenged Simacore to a test of knowledge as Fixit, Denny, and Russell hid from behind his left leg. Simacore went first and gave Grimlock a the classic "two trains leaving different cities" problem. Grimlock was able to answer Simacore's question as he revealed that Underbite had destroyed Nuon City which it no longer exists nor does it have a train. Grimlock has his own very simple question for the Decepticon and has regained his mobility to boot, flattening Simacore as he ponders Grimlock's little puzzle then he rescued Bumblebee and Strongarm from being fired at by the particle accelerator. Back at the scrapyard, Grimlock was complimented by Bumblebee and Strongarm for his performance in the field. Grimlock opts to have another attempt at the tests. He promises that he will take his time and asks Fixit if there is a version of the test with pictures.
In Misdirection, Grimlock watched with Bumblebee, Strongarm, Fixit and Denny as Russell performed a magic trick. When a wounded Steeljaw turned up at the scrapyard, Bumblebee, Strongarm and Grimlock placed and secured him in a stasis pod before they followed the trail of energon Steeljaw had left to a disused drive in where they encountered Scorponok, Scorponok's Mini-Cons, Crazybolt and Slicedice. Grimlock and Bumblebee provided cover for Strongarm to go to the scrapyard after Bumblebee told them they were tricked by Steeljaw. Grimlock battled Scorponok with some of the mics at the drive in but ended up being smacked by Scorponok who used a pole. Grimlock was temporarily out of the fight and was used a hostage by Scorponok. Bumblebee's "flim flam" trick on the Decepticons provided a distraction for Grimlock. When he regained himself, Grimlock was able to help Bumblebee defeat and capture the Decepticons and brought them back the scrapyard where Steeljaw had already freed some of the prisoners and escaped.
In Bumblebee's Night Off, Grimlock was increasingly bored as the Autobots tried to find the cable which the Decepticons were looking for, but he managed to find it, shortly before he was blasted by Springload, and then inadvertently by Bumblebee. He turned down staking out a Rear Axle concert in favor of practicing his sculpture, but joined Strongarm in trying to come to help Bumblebee when Bisk turned up at the concert. At the scrapyard, Grimlock was impressed at Bumblebee and Russell's excitement from the concert.
In Impounded, when Grimlock almost caused a disaster and exposed himself to some humans while trying to apprehend Silverhound, Bumblebee banned him from going on missions. However, while Bumblebee and Strongarm were both detained in an impound lot, Fixit came up with a crane disguise for Grimlock to use. Fixit and Grimlock are holding up traffic when the former picks up a silent alarm alert. When they reached the scene, upon realizing he was trapped in his disguise, Grimlock ends up toppling over. Quillfire orders Back and Forth to unleash their opposing magnetic powers on Grimlock, threatening to tear him apart. Fixit uses his drill hand to fling parts at the two Mini-Cons, resulting in the three Decepticons fleeing shortly before Bumblebee and Strongarm arrive. Though skeptical of Grimlock's new disguise, even though they were not expecting Grimlock to be in, Bumblebee is convinced to let him come along. Fixit determines that Quillfire's next likely target is a nearby truck stop, so they leave the humans behind and head there. When Quillfire got the best of Bumblebee and Strongarm, he attempts to escape but Grimlock uses his crane hook to catch him by the rear bumper and spin him around repeatedly. Quillfire and his Mini-Cons were captured, prompting Bumblebee to allow Grimlock back into the field much to Grimlock and Fixit's singing on the way home.
In Portals, after an incident that Grimlock and Strongarm was involved while they attempted to work on a turret in the Scrapyard, Bumblebee assisted them out of their predicament. However, when Fixit's repairs to the GroundBridge brought Soundwave to Earth, Strongarm and Grimlock were knocked out by the Decepticon. Grimlock attempted to take on Soundwave himself by punching him but ended up being zapped to the floor along with Strongarm. Later, they recovered and were sent by Soundwave through one of his portals to the quarry with Laserbeak. There, they were able to take out Laserbeak and went back to the scrapyard as Grimlock threw the Mini-Con back into the shadowzone after Soundwave. Bumblebee was impressed at his team who all worked well without him but they all pointed out, even with some compliments from Grimlock, that they were just following his plan.
In Graduation Exercises, while following another mission, Grimlock joined up with the stealth team via the GroundBridge, and carried an injured Drift back to base.
In Decepticon Island (Part 1), during a mission where Grimlock used his crane disguise again with the Autobots, he overheard the concept of "team within the team" and wanted to team up with Drift, who disagreed. After a chance encounter that resulted in Ratchet joining the team and interrogating a captured Clampdown who faints, the Autobots got a lead to the location of the group of Decepticons by Toolbox who escaped the Decepticon island and informed the team all about the Decepticons and how they took control. Grimlock thought of going with Drift and attacking the island together, but that plan was unconvinced. Later, Fixit, Toolbox, and Russell helped Grimlock get ready as they prepared him to look like a Decepticon with his symbols on his shoulders repainted with Decepticon symbols. Grimlock drove Denny's boat with his Autobot allies who were all pretending to be incapacitated to look for the island. Grimlock was contacted by the Decepticons and with some fake story provided by Bumblebee, Grimlock was able to convince the Decepticons to reveal the island as it appeared before them. Two Decepticon guards came out to investigate as Grimlock kissed the floor of the ship acting as if he was glad to be "home". When the guards became suspicious, Grimlock knocked them out when he smashed their heads together. The Autobots made their way by sneaking past some Decepticons but when they came to a room where their presence was known, they were soon surrounded by Decepticons.
In Decepticon Island (Part 2), when the Autobots split up, Grimlock tagged with Strongarm and Sideswipe. They ended up heading in a communications room where they started to use its operating systems to free the captive Mini-Cons. Groundpounder and Thunderhoof came in the room to fight the Autobots which Groundpounder wanted to settle a score with Grimlock from their last encounter and attacked the Dinobot. As they fought, Groundpounder seemed to have the advantage over Grimlock as he pinned the Dinobot to the wall and used his "Fiery Fists of Furnax" on him. Although Grimlock seemed defeated, Sideswipe managed to incapacitate Groundpounder and Thunderhoof with a high frequency signal. After using the communications equipment to free the Mini-Cons, the trio escaped the ship before the cryo-gas bomb froze everyone aboard. In the aftermath, Drift accepts Grimlock as his "teamie" and Grimlock remains on Bumblebee's team as they headed back to the scrapyard together.
In History Lessons, Bumblebee took his team on a tour of interesting locations on Earth, culminating in them visiting the remains of Autobot Outpost Omega One, only to find a strange bomb had been set up to detonate. Grimlock was partnered with Strongarm when the team split up, only to end up stepping on a mine. He was unable to move for fear of setting the mine off, until Bumblebee found him and revealed that the "mine" was just an old armor buffer.
In Strongarm´s Big Score, when Bumblebee split up the team to search sites of Cybertronian significance, Grimlock was assigned look in western China. The team was accidentally bridged back to the scrapyard instead of Mount St. Hilary because Denny and Russell didn't know what they were doing.
In Pretzel Logic, after one too many accidents, Grimlock was disgruntled when Bumblebee only assigned him one mission in the search for Cybertronian relics. During his mission, he encountered Brother Gunter, who set about teaching him patience via the medium of pretzel manufacture. Thermidor and Tricerashot turned up at the monastery, resulting in Grimlock calling in the rest of the team, however ultimately it was the patience he'd learned that allowed Grimlock to defeat the scavenger later on. Grimlock returned to the monastery with Bumblebee who went through the same process of making a pretzel like Grimlock did originally.
In Mighty Big Trouble, when Team Bee found a high energy pulse generator in Egypt, Grimlock carried it back to the scrapyard using his crane mode, however the device was destroyed anyway when it threatened to fry their brains. Following an invasion of the scrapyard by the Weaponizer Mini-Cons, the team lost both their own Mini-Cons and their leader, after they were abducted by Starscream.
In Mini-Con Madness, joined by Optimus, the team split up to search for Starscream. Grimlock was first on the scene when Strongarm and Sideswipe ran into the Weaponizer Mini-Cons, but the ensuing hostilities ended when the Mini-Cons recognized Optimus, and the two groups teamed up. A short time later, they ran into the Scavengers, and then during the fight with them, the Mini-Cons were captured by Starscream.
In Worthy, Grimlock linked with Tricerashot, who'd avoided being captured, and took out the Scavengers. He and the rest of the team located Starscream's ship, and during the ensuing battle with the Decepticons, they were knocked out by Starscream. They eventually managed to defeat Starscream, despite him successfully merging with the Weaponizer Mini-Cons, by dragging him down into range of Fixit's signal so he could be de-merged. After farewelling Optimus and the Mini-Cons, Team Bee split up to search more Cybertronian sites.
In King of the Hill (Part 1), without any Decepticons to punch, Grimlock passed his time playing tic-tac-toe with his own tail. He joined Bumblebee and Drift as they traveled to Grand Valley to face a Decepticon.
In King of the Hill (Part 2), Grimlock found himself at a disadvantage as he was unable to outrun Heatseeker's guided missiles, but he managed to serve as a distraction for Bumblebee and Drift to move in. The mission ended with the entire team somehow being merged into one robot, though they were unconscious at the time.
In Defrosted, while he was impressed by the abilities of Drift's pupils, Grimlock decided to become Drift's "poodle" too. As the team attempted to capture Crustacion in Antarctica, Grimlock's attempts to put Drift's teachings into practice were surprisingly successful, and he was instrumental in capturing the 'Con.
In Blurred, Grimlock and the rest of the team joined up with the Rescue Bot Blurr as they attempted to recapture Ragebyte. The mission was successful as Ragebyte was placed back in a stasis pod.
In Sphere of Influence, Grimlock, along with the rest of the team, found himself drawn to possess the Sphere of Doradus thanks to the strange energies it gave off. He was later able to overcome this desire thanks to his love of punching, and took part in the capture of Springload.
In Bee Cool, Grimlock was part of a mission to West Rock, and used his crane disguise to block the city's only exit to prevent Dragstrip and Wildbreak escaping.
In The Great Divide, during another attempt to capture Dragstrip, a methane explosion caused the team to again merge into a giant robot, though Grimlock was disappointed to find he was the legs. Afterwards, the team had to cope with having two Sideswipes as they continued to try to get back the relic Dragstrip had stolen as the two Sideswipes worked together to bring him down and take the relic to reverse the effects on Grimlock and the others.
In Get a Clue, Grimlock and the rest of the team captured three Decepticon brothers as a result of Strongarm employing her detective skills.
In Out of the Shadows, Grimlock and Sideswipe were temporarily fused together during another of Fixit's combiner experiments. They and the rest of the team helped Drift recover his two Mini-Cons students after they were kidnapped by the Decepticon Shadow Raker.
In Disordered Personalities, another of Fixit's combiner experiments led to the Autobots temporarily switching bodies. Grimlock reveled in having Drift's vehicle mode, and gleefully took part in a road race in an attempt to stop the Stunticons, though he had difficulty working with Drift's Mini-Cons.
In Guilty as Charged, the team attempted to help Strongarm's friend Nightra after she turned up apparently being pursued by Blastwave, only to discover that Nightra was the criminal being hunted while Blastwave an Autobot bounty hunter. When the deception was exposed aboard Blastwave's ship, Grimlock put his all into hanging onto the rest of the team as they were nearly blown out of a cargo bay, before he managed to close the bay door.
In The Golden Knight, Grimlock developed an interest in art and started off by making a sculpture of Strongarm.
In The Fastest Bot Alive!, after allowing Fixit to experiment on him, Grimlock developed uncontrollable super speed. Despite Bumblebee restricting him to base, Grimlock - inspired by Russell's reading a Captain Plasma Beam comic to him - believed he could be an effective superhero and joined in on a mission to recapture Simacore. This didn't go well, but he did eventually successfully defeat the Con, and he took pride in Simacore's having declared him to be the Orangucon's "greatest foe".
In Railroad Rage, Grimlock, no longer with the aid of super-speed, took part in a mission to prevent the Stunticons from stealing the power source for a high-speed maglev train.
In Combine and Conquer, Grimlock and the rest of the team finally managed to combine into Ultra Bee during another mission against the Stunticons.
In Moon Breaker, a message from Windblade sent the team to the Moon, where they again combined and managed to defeat the Stunticons once and for all.
In Exiles, Russell and Grimlock began making video diaries to keep the absent Drift up-to-date. Their latest effort was interrupted by an attack which drove the Autobots from the scrapyard and forced them to seek refuge in the nearby cave system. Decepticon signals led them to the culprits — Steeljaw and his pack, and the ensuring battle endangered Crown River Dam.
In Breathing Room, with the Autobots finding the cramped quarters of the caves inconvenient, Denny and Russell got Grimlock to enlarge it using his rock-smashing skills.
In Prepare for Departure, left on monitor duty, Grimlock was distracted and missed the detection of some Decepticon signals. As a result, he became hyper-sensitive about remaining professional and not having fun on the job, which almost resulted in the Decepticons getting away with some nuclear waste until Sideswipe snapped him out of it.
In Prisoner Principles, Grimlock took part in a mission which resulted in the defeat and capture of (most of) Steeljaw's pack at the nuclear plant.
In Collateral Damage, Grimlock took part in the defeat of Soundwave, preventing the Decepticon from irradiating the entire planet. He later dressed up as "the monster from Dimension Aaargh" for Sideswipe's performance of Showcase of Shivers.
In Something He Ate, the Autobots returned to the scrapyard and Grimlock was tasked with securing the prisoners, only to let Underbite escape. He and the other Autobots were forced to chase the 'Con, who randomly teleported thanks to a chunk of space bridge he'd eaten.
In Sick as a Bot, after Bumblebee, Strongarm and Sideswipe were infected with a nano virus, Grimlock rushed off to try to capture the Decepticon. He only succeeded once the newly-arrived Bulkhead helped him slow down and come up with a plan.
In Five Fugitives, during a pursuit of Steeljaw, Grimlock and the others found themselves arrested by Dropforge. They were able to escape with Denny and Russell's help and both foiled Steeljaw's plan, and freed Dropforge from the mind control signal he was being controlled by.
In Enemy of My Enemy, Optimus arrived once more, sending Grimlock and the rest of the team to Cybertron where the Autobot council were using mind control on the population. On arrival, the Autobots were surrounded by security.
In Freedom Fighters, with the help of Dropforge and Steeljaw, they were able to gain entry to the High Council Tower. After they discovered the council were actually Decepticons, Grimlock decided the best way to eliminate the mind control was to smash everything. He then took on Treadshock and managed to knock him out with a tail smash. A battle ensued with the Autobots and Decepticons taking on their combined forms for a last ditch struggle for Cybertron, and the Bee Team eventually prevailed. In the aftermath, Grimlock and the others returned to Earth as newly appointed ambassadors and ended up chasing after Steeljaw again.
- "Pilot (Part 1)"
- "Pilot (Part 2)"
- "Trust Exercises"
- "More than Meets the Eye"
- "As the Kospego Commands!"
- "Collect 'Em All"
- "True Colors"
- "Rumble in the Jungle"
- "Can You Dig It?"
- "Adventures in Bumblebee-Sitting!"
- "Hunting Season"
- "Out of Focus"
- "Even Robots Have Nightmares"
- "Some Body, Any Body"
- "One of Our Mini-Cons Is Missing"
- "Deep Trouble"
- "The Champ"
- "The Trouble with Fixit"
- "Similarly Different"
- "The Buzz on Windblade"
- "Ghosts and Impostors"
- "Battlegrounds, Part 1"
- "Battlegrounds, Part 2"
- "Overloaded, Part 1"
- "Overloaded, Part 2"
- "Metal Meltdown"
- "Bumblebee's Night Off"
- "Graduation Exercises"
- "Decepticon Island (Part 1)"
- "Decepticon Island (Part 2)"
- "History Lessons"
- "Strongarm´s Big Score"
- "Pretzel Logic"
- "Mighty Big Trouble"
- "Mini-Con Madness"
- "King of the Hill (Part 1)"
- "King of the Hill (Part 2)"
- "Sphere of Influence"
- "Bee Cool"
- "The Great Divide"
- "Get a Clue"
- "Out of the Shadows"
- "Disordered Personalities"
- "Guilty as Charged"
- "The Golden Knight"
- "The Fastest Bot Alive!"
- "Railroad Rage"
- "Combine and Conquer"
- "Moon Breaker"
- "Breathing Room"
- "Prepare for Departure"
- "Prisoner Principles"
- "Collateral Damage"
- "Something He Ate"
- "Sick as a Bot"
- "Five Fugitives"
- "Enemy of My Enemy"
- "Freedom Fighters"
In Robots in Disguise, he had Decepticon logos and they are located on his shoulders until Fixit replaced them with Autobot symbols. Grimlocks' robot mode is green and black all over and his face is a light orange color along with his blue colored optics.
In RID, his dino mode is colored green, black and little bit of gray. He has some yellow colored places around his chest and face area. He has eyebrows, nostrils, and two well sized arms. He also has a golden piece in the center of his forehead.
In Robots in Disguise 2015, Grimlock is shown to be jovial, friendly and likes to break things or use violence as a way of getting things across, which gender does not matter in a punching situation for Grimlock. His preferred method of attack is charging in and beating the lugnuts out of his enemies. Grimlock is also shown to be more mature and a bit smarter than he was during the War for Cybertron, and he has better speech patterns and is less arrogant. However, he is still shown to be easily angered on some occasions. Because of his good natured personality, it remains unknown why he was placed on the Alchemor in the first place.
In True Colors, he stated that he is "not a bad guy".
In Even Robots Have Nightmares, Grimlock's fear was in his dream as he was menaced by a kitten and hanged from a tree to avoid it.
Despite his aggressive side, Grimlock is very helpful and a real appealing Dinobot. He likes to hang out with his friends, show off his fighting skills and mostly punch bad guys.
Powers and abilities
In Robots in Disguise, he appears to be the stronger member on his team as Bumblebee stated in Deep Trouble, that Grimlock is the team's muscle. He is capable of standing toe-to-toe with his rival, Underbite in repeating occasions, his fighting style is similar to those of professional wrestlers.
- Grimlock’s debut in Robots in Disguise was initially the focal point of discussion amongst fans, with a great deal of debate about whether or not this jovial take on the character was intended to be the same character who appeared in the Fall of Cybertron video game and tie-in comics. Some of the discrepancy in Grimlock’s characterization and origin story in Robots in Disguise can be attributed to the fact that Grimlock was not originally slated to be a member of the cast, with his role originally filled by an unnamed Transformer who would have become a red Stegosaurus. This character was scrapped in favour of Grimlock at Hasbro's request. Regardless, Transformers: Prime Wiki considers the Fall of Cybertron Grimlock and the Robots in Disguise Grimlock to be two different characters.
- Grimlock was voiced by Gregg Berger who voiced him in G1 cartoon. Grimlock was supposed to appear in Beast Hunters with Berger reprising his role but was cut for time. His arc would have featured him feeling like an outcast and his fights with Predaking. It is unknown if the other Dinobots would have appeared.
- High Moon Studios said they based this Grimlock on the Marvel Comics' character, The Incredible Hulk. He is a tortured soul and becomes stronger and more powerful when angered.
- When Grimlock transforms into a T-Rex, his form becomes bigger, similar to Predaking.
- Given that Grimlock was from Kaon, it is unlikely he was born with a name. Whether he took a name for himself like Megatron or was given one by the Autobots remains unknown.
- Grimlock appears in the sequel to Transformers Prime series, Transformers: Robots in Disguise. His appearance doesn't reflect the previous depictions of the character in related media such as the War for Cybertron and Fall of Cybertron games or Rage of the Dinobots comics-it is unknown why this is.
- Alongside Bumblebee, Grimlock is one of the oldest members of the new Autobot team on Earth as Strongarm and Sideswipe are considered "teenagers" by Cybertronian standards.
- In Even Robots Have Nightmares, it is revealed that Grimlock is claustrophobic, as he said "I don't like small, dark places!" Also, with the arrival of the stray cat in this episode, he is shown to be ailurophobic. He is even phasmophobic, as he once said he doesn't like movies with ghosts in them.