Optimus Prime (sometimes Nemesis Prime), is the leader of the Autobots. Long ago, he was the novice to the Great Sentinel Prime and the humble leader of Cybertron's science division, which studied the AllSpark and were protected by Lord High Protector Megatron's military. When Megatron was corrupted by the Fallen, Optimus discovered that he was the last of the Dynasty of Primes hidden away when the Fallen destroyed their lineage. In response to Megatron's attempts to seize the AllSpark and conquer other worlds, Optimus assumed his proper title and rallied the Autobots to stand against the Decepticons. Before the disappearance of Sentinel, Optimus is handed the leadership of the Autobots.
As obsessively as Megatron strives to achieve his objective, Optimus is equally as dedicated to stopping him even at the cost of his life, his world and - if necessary - his own people. It was on his order that the AllSpark was jettisoned into space, dooming Cybertron to a slow death and his people to a nomadic life. The sacrifices he has made weigh heavily on his spark, but they must be done for there is no other choice. He knows the ambitions that lurk in his brother's spark and they must never see the light of day. Lives must be kept free from the threat of Megatron's tyranny, no matter the cost. This obsession with the defeat of Megatron has robbed Optimus of some of his early idealism. This has created a certain ruthlessness beneath his otherwise honest and caring personality. Prime is not one for second chances and is willing to consider any action that might lead to victory, short of directly sacrificing those he cares about.
Personality & Character
Optimus Prime led the search for the All Spark in the Ark, a transport vessel. When they came across an abandoned solar system, they located a vessel of strangely Cybertronian design, seemingly of Decepticon make. When the vessel fled to the surface of a planet, Prime dispatched Bumblebee to investigate while he and the other Autobots battled Decepticons from the Nemesis. Prime managed to defeat Blackout, Scorponok, and Frenzy all on his own. After losing touch with Bumblebee, Prime went down to locate him on the planet, where they were attacked by Starscream and the alien ship. They fell into a cavern network, where they were further attacked by indigenous worms.
During their flight from the creatures, Optimus Prime and Bumblebee came across the alien vessel. Prime realized that they were trying to surrender, so the Autobots communicated with its crew. Optimus explained that they came in peace, "freedom is the right of all sentient beings," Starscream tricks everyone, and so on. However, the creatures, who called themselves "humans", explained that they held Megatron, whom they called the Ice Man, on their home world, Earth. Realizing the destruction Megatron would wreak upon the humans if he escaped, and that the humans would be unable to defend themselves effectively, Prime vowed to see them return to their world to warn it. Prime was able to blast an opening in the cavern, and the group escaped. As they returned to the Ark, Prime began to speculate that the All Spark was what drew Megatron to Earth.
In the ensuing battle with the Decepticons, Prime was in the difficult position of fighting Starscream and protecting the human ship. His distractions allowed Bonecrusher to spear him with his tail. The difficult state nearly gave Starscream the chance to kill him, but the humans saved Prime's life by damaging Starscream, who destroyed them. Optimus Prime was inspired by their courage and sacrifice, and resolved to locate Earth before the Decepticons did—and hopefully before Megatron came back online  .
Optimus Prime appears on Cybertron, in fighting alongside the Autobots against the Decepticon troops. As the Autobots are seemingly overwhelmed by the bulk of the Decepticon forces, Optimus shows up to briefly repel the attackers. He then requests for B-127, an Autobot scout, who shortly arrives after taking down a bunch of Seekers. Upon witnessing the arrival of Soundwave, Shockwave and Starscream, Optimus orders the Autobots to retreat to the launchpad tower, which they intend to use as a means of escape from Cybertron. Upon reaching the tower, as his fellow Autobots make their escape, Prime instructs his scout B-127 to go to Earth and establish a base for them. He tells him to reconnoiter the planet and protect it from Decepticons, as they will be finished if the Decepticons found out. As B-127 then makes a run for his own escape pod, the launchpad tower is bombarded with gunfire from Starscream and his Seekers, who were ordered by Shockwave to destroy the tower. Optimus stays behind to delay any pursuit and divert their attention from the fleeing Autobots.
As Optimus continues to fight off more Seekers, Soundwave appears and ejects Ravage from his torso to attack the Prime. The mechanical feline fared much better than his full-sized comrades, as he managed to evade a shot from Prime's blaster and knock him down, although not long after Ravage gets punched in the jaw, sent stumbling back to his master. The distraction caused by Ravage allowed several Decepticons to converge on a recovering Optimus Prime, though it was unknown what happened afterward.
By the end of the film, Optimus is shown to have arrived on Earth, as he rendezvouses with B-127 (now known as Bumblebee) on the Golden Gate Bridge, in the form of a red Freightliner semi-truck. He later convenes with his scout in a forest, commending his efforts in keeping Earth safe.
The leader of the Autobots, Optimus Prime came to Earth shortly after Bumblebee signals his comrades with his beacon. Upon atmospheric re-entry, Prime managed to land outside of Tranquility's inhabited areas. While Sam and Mikaela watched, Optimus transformed in his protoform and fled his landing place. From atop a hill, he quickly trans-scanned the form of a 1997, Peterbilt 379 semi truck, thus configuring his body to transform into it. Prime, Jazz, Ratchet, and Ironhide met up with Bumblebee and his human friends, Sam Witwicky and Mikaela Banes in an alley. In one of the most extended transformations in the multiverse, Prime assumed his robotic form before the stunned humans. After confirming Sam's identity, Prime introduced himself and his team. When Mikaela asked of the Autobots' intentions, Prime explained the search for the All Spark, the betrayal of Megatron, and why Sam was important to their search.
Glasses that belonged to Sam's ancestor, Captain Archibald Witwicky, contained the location of the All Spark encoded across its lenses, so Optimus Prime ordered his troops to wait outside Sam's house while Sam and Mikaela searched inside for the glasses. Much to Sam's exasperation, Optimus Prime, in his impatience, clumsily ruined his parents' garden. Prime's attempts to hide, such as having the Autobots transform into vehicle mode right in the backyard; were also less than satisfactory. Ultimately, Sam came so close to a panic attack that Prime was forced to order the Autobots to fall back. As Prime lectured his team on their supposed inability to remain quiet, Ratchet got himself shocked by walking into some power lines, then crushing a greenhouse during his fall, causing further problems thus making Ron think there was an earthquake and ran under the table asking Judy to "duck and cover." When the parents came to investigate, Prime's attempt to avoid discovery caused the house to shake, as Ron jumps into an old cast-iron tub and stated that he hates earthquakes; though this was to their benefit, as the father assumed that the damage to the yard was the result of an earthquake. Ironhide suggested that he should kill the parents as they were very irritating, but Optimus scolded his old friend. Despite all this, their presence remained undetected until Sector Seven arrived (in a convoy of GMC Yukons) and abducted Sam, Mikaela, and Sam's parents.
Optimus Prime sent the Autobots in pursuit of the SUV that contained Sam, Mikaela, and Sector Seven's director, Agent Simmons. Prime intercepted the vehicle carrying their young human friends, ripping the roof of the vehicle off, with the other Autobots disarming the agents, and made it perfectly clear to Simmons how ticked off he was at him for trying to apprehend the two children, regarding this as a bad move on Simmons' behalf. Optimus then ordered his comrades to relieve the agents of their weapons, and attempted to interrogate Simmons. The agents' lack of surprise at their appearance indicated that they had seen Cybertronians before, but Simmons refused to reveal any information. With a Sector Seven backup team en route, Prime ordered the Autobots to scatter, while he took Sam and Mikaela. While hiding under a bridge, Mikaela and Sam slipped and fell off Prime's shoulder. Bumblebee managed to catch them before impact, but was captured, and Sam and Mikaela recaptured, by the organization after their retreat.
Optimus Prime, now in possession of the glasses which could tell him the location of the All Spark, regretfully left Bumblebee in Sector Seven's hands, knowing that if they went after him, they would have to use deadly force. After regrouping the next day, Prime used the glasses to locate the All Spark. Jazz raised objections to leaving Bumblebee behind, but Prime remained firm in his belief of not harming the humans. Ironhide seemed okay with using deadly force, stating the humans were a "primitive and violent race", but Prime countered that when their time had come, the Cybertronians had been little different. Going on to explain the potential he saw in the humans, as well as reminding them that "freedom is the right of all sentient beings", Prime revealed to the Autobots his real plan for the All Spark: if they could not defeat the Decepticons, Prime intended to merge the Cube with his spark. Though this would destroy the All Spark, Ratchet cautioned Prime against this, as it would also kill him as the Cube is raw power. Prime believed that this was acceptable, vowing not to let another race suffer the mistakes of the Transformers. The glasses placed the All Spark at Hoover Dam where, luckily, Bumblebee and the young humans were taken.
Optimus Prime's team met up with Sector Seven, Bumblebee, Sam, and Mikaela en route, who had planned to hide the All Spark in nearby Mission City. While on the highway CA-210, he was attacked by Bonecrusher, who managed to tackle Optimus and drag him over the edge of a freeway overpass. During the battle, Optimus struck the hate-filled Decepticon so hard in his face, his left optic popped out. As the Decepticon swung his claw wildly, Optimus drew his Energon sword from his right arm and cleaved off the Decepticon's right arm. He then proceeded to grab Bonecrusher in a headlock, and drive his blade through Bonecrusher's neck, severing his head.
Optimus arrived at Mission City and challenged the Decepticon Leader. Megatron discarded the remains of Jazz, and called out the Autobot's name. Millennia in the ice had done nothing to lessen Megatron's hatred of his brother, and he launched himself in jet mode at the Autobot leader. Optimus leaped and grabbed hold of the wings, which was a really bad idea, as Megatron drove himself and Prime through an office block.
As they flew out of the building onto the street below, Megatron transformed and leapt on top of Prime, declaring the humans undeserving of life. Prime rejected his claims, saying that they deserved to choose for themselves. Megatron threw Prime across the street, declaring that if he wished to defend the humans, Prime could die with them. He then formed his fusion cannon from his forearms. The power up time allowed Prime to draw his ion blaster and fire hitting Megatron. The Decepticon used the momentum to spin around, then used the fusion cannon to blast Prime across the street into another building. Megatron then resumed the hunt for Sam and the All Spark.
Tracking Megatron to the deserted building, Prime barely managed to catch Sam after Megatron knocked him off the roof. Telling the boy to hold onto the Cube and stay close to him; Prime attempted to scale down the building, but Megatron jumped on Prime, causing them both to fall down hard onto the street below. Sam survived, however, Optimus told the boy that if he could not defeat Megatron, that Sam must put the All Spark into his chest which would destroy it. As Sam sought cover, Optimus faced down Megatron, informed him that, "At the end of this day, one shall stand, one shall fall". Unfortunately, Megatron, even after years of stasis, proved to be far too powerful for Prime to defeat alone. The unit led by Lennox and the Raptor squadron laid down suppressing fire as Megatron reached for the All Spark, until Optimus finally took him down by sweeping his legs. Still, Megatron continued crawling toward the cube. Believing he had lost, Optimus implored Sam to put the All Spark into his chest. Sam instead thrust it into Megatron's chest, killing the Decepticon leader and destroying the All Spark.
As Optimus watched his brother die, he remorsefully stated there was no other choice. He also told Sam he owed him a debt of gratitude for saving his life, but was then informed that his old friend Jazz had not survived. Prime sadly eulogised his comrade, then commented that they had gained new comrades in the humans, and was honoured by their bravery. Bumblebee, who had finally regained his voice, requested permission to remain with Sam Witwicky, to which the young human eagerly agreed and Optimus approved. He noticed a fragment of the All Spark in Megatron's chest cavity and removed it, then permitted the humans to dispose of the Decepticon corpses by dumping them into the
deepest 2nd deepest part of the ocean.
Though Megatron was killed and his Decepticons were defeated, the All Spark was destroyed, leaving the Autobots unable to restore Cybertron. The Autobots elected to remain on Earth and Prime sent a message into deep space to any surviving Autobots in the Galaxy to come to their new home on Earth, their long years of searching having finally having come to an end. As the other Autobots rested, Optimus Prime looked to the sky, hoping his message had been heard  .
With the destruction of Megatron, Optimus Prime thought that he was finally, after millions of years, at peace. Little did he know that the escape of Starscream would draw dozens of new Decepticons to Earth. The desire that burns brightest in his spark is that the war will soon end. He is determined to see that end come, and so he works with his human comrades and the other Autobots to hunt the Decepticons that have come down to Earth, and destroy them one by one.
When in Shanghai along with Ironhide, Sideswipe, Skids, Mudflap and Arcee, they battled the giant Decepticon Demolishor. Airlifted into the area, Optimus Prime climbed atop and brought Demolisher down by shooting him several times in the head while Ironhide destroyed his giant wheel, sending the Decepticon crashing into the ground. Mortally wounded, Demolisher taunted Optimus with a warning: "The Fallen shall rise again". Optimus disagreed and delivered a point blank blast right through his face, killing him mercilessly.
Optimus and the N.E.S.T. returned to Diego Garcia where the National Security Advisor questioned the Autobots continued presence on Earth and proposed having the Autobots leave, which Optimus agreed to if asked.
After Ravage and the Microcons stole the All Spark shard, Optimus turned to the one ally he has that he believed could help convince the government: Sam Witwicky. Optimus met with Sam in a cemetery after sending Bumblebee to retrieve him, but Sam refused to help, believing that he wasn't the man for the job and that Optimus didn't need his help. Optimus was clearly frustrated, saying that they need Sam's help more than he knows.
Later, Optimus and Bumblebee came to Sam, Mikaela and Leo's rescue after they were captured by Decepticons. Drawing his ion blaster and barrage cannon, Optimus smacked and blasted Starscream out of the warehouse before landing a point-blank range shot on Megatron, sending him flying. As Megatron fled, Optimus transformed and drove Sam to safety. Prime drove into a forest, but Megatron sped towards them in his vehicle mode from behind. Megaton fired some stray shots at Prime in his tank form before jumping onto Prime, intending to rip Prime apart while he was still in truck form. However, Optimus transformed at the last minute and punched Megatron while both robots were in mid-air. Megatron then tackled Prime, and both of them hurtled to the ground, while Sam hid on Prime's orders. Prime proceeded to beat Megatron with a tree and punched him in the back, before slashing him with one of his energon swords. This prompted Megatron to call Grindor and Starscream, who come crashing through the trees. Prime grappled with Starscream, kicking Megatron away at the same time, before holding Starscream up-side down in the air and kicking him in the head. However, the three decepticons formed a bully circle around Prime, with Grindor and Starscream shooting their machine guns at Prime. Megatron threw him at a tree and kicked him in the face so hard, his mouth guard broke. Starscream shot at him more before Megatron blasted him backwards with his Fusion Cannon.
Megatron questioned why Prime was sacrificing the future of the Cybertronian race over a single human life. Urged by Sam to keep fighting, however, Optimus reminded them that they would "never stop at one", deployed his second energon sword, and fought back at the decepticon trio. Optimus slashed at all three Decepticons, in the process cutting off Grindor's right arm and once again grappling with Starscream and using Starscream to swirl around the Decepticons by flipping over his back. Optimus cut Starscream's right arm off with his energon hook, and used it as a club against the Decepticon, knocking him out. Optimus then jumped on top of Grindor and tore his head apart, killing him. However, Optimus was brutally impaled from behind by Megatron, fatally injuring him. Megatron commented on his strength, before blasting his spark with his fusion cannon. Collapsing to the ground, Prime's last words were "Sam, run... ru...".
The Autobots arrived seconds later, forcing the Decepticons to retreat. Optimus' body was airlifted to Diego Garcia by N.E.S.T and later transported to Egypt upon Sam's request, in hopes of resurrecting him with the Matrix of Leadership. He succeeded, with Optimus exclaiming both his surprise and happiness that Sam saved him. However, before Optimus was able to fully recover, The Fallen arrived, knocking down Prime and the other Autobots and stealing the Matrix to power the Solar Harvester.
Jetfire, who was mortally wounded, ripped out his own spark and gave Optimus his parts to use to make himself more powerful to defeat The Fallen as "only a Prime can defeat The Fallen". Ordered by Ratchet, Jolt used his electricity charged whips to fuse Jetfire's parts with the weakened Optimus Prime. Optimus, using Jetfire's engines, flew to the top of the pyramid and tackled The Fallen. Optimus destroyed the Solar Harvester with a single shot with his rifle. After they fell to the ground, Optimus and the Fallen had a brief fight, before Megatron grabbed Optimus, and fought him himself. Optimus used Megatron's own cannon to blow a quarter of his face off, slice his right arm off, and finally blast him into two walls with a huge blast from his jet engines. Optimus then continued his fierce battle with The Fallen, eventually managing to impale him through the shoulder with his own spear, rip off his face off, and finish him off by ripping out his spark. Realizing they'd lost, Starscream and a severely weakened Megatron fled. Victorious, Optimus discarded Jetfire's components and rejoined his companions.
Later, on the deck of an aircraft carrier, Optimus joined Sam and thanked him for saving his life to which Sam responded "You're welcome" and thanked him for believing in him. Optimus then broadcasted a message about the shared history and future of the humans and Transformers race  .
Optimus, now with a trailer that transforms into a weapons pack that can also acts as flight gear, traveled to Chernobyl with N.E.S.T. where they retrieved a mysterious piece of metal part before coming under attack by
Shockwave's monstrous "pet" Driller. Optimus grabbed a sword and shield from his weapons pack and cut loose the piece of metal parts. Shockwave emerged from the Driller to glare at Optimus before fleeing with his pet. Optimus was shocked and surprised to discover that the mysterious piece of metal was an engine part from the long-lost Ark.
The Autobots return to NEST with the part and Optimus remained in alternate mode and refused to speak to anyone at first even when Charlotte Mearing approached him. Eventually, however, Optimus transformed rather violently and confronted Mearing about the part and the fact that they were told that everything humanity knew about the Cybertronians had been told. Mearing explained that it was kept secret from everyone except a very few people and brings in Buzz Aldrin to explain. After learning of the Ark being crashed on the moon, Optimus decided to take the Xantium to investigate the wreckage.
Optimus and Ratchet traveled to the moon and entered the Ark where they found Sentinel in stasis lock with five of the pillars, including the Control Pillar. They recovered the pillars and Sentinel and returned to Earth with them.
Upon their return to Earth, the pillars were put into a vault under the human's control and Optimus prepared to use the Matrix of Leadership to revive Sentinel. After the arrival of Sam Witwicky, Optimus successfully revived Sentinel, who initially attacked him out of confusion before calming down after learning where they are. The two then explained to the humans about the space bridge and the threat that would be posed if the Decepticons learned of it and got the pillars.
Afterwards, Optimus took Sentinel for a drive to show him some of the planet. Sentinel was impressed and Optimus humbly offered him the Matrix of Leadership after lamenting what could've happened if Sentinel had led the final battle of the war. Sentinel refused the Matrix and told Optimus that he is now the teacher, not him.
Later, Optimus rushed back to the base after Sam discovered what the Decepticons were up to, but is too late as Sentinel had revealed his true colors, murdered Ironhide, and taken the pillars.
At the National Mall, Optimus confronted Sentinel, who was using the space bridge to bring an army of hundreds of Decepticons to Earth, and pleaded with him to stop. When Sentinel refused, Optimus tried to fight the treacherous Autobot, but was no match for his former mentor. Sentinel easily pinned him down and Optimus demanded an explanation for Sentinel's betrayal. Sentinel claimed that he did what he did to save Cybertron before leaving, telling Optimus that he was lucky he didn't kill him and that he would one day understand.
After Sentinel made an ultimatum to the United Nation, the Autobots were ordered to be expelled from the planet. Near the Xantium, Optimus met with a deeply saddened Sam who tried to get him to stay. Optimus informed Sam that they had to go and gave some words of wisdom to his old friend about not losing faith in yourself and that the war was the humans' now. Sam, under threat against his girlfriend, tried to find out the Autobots plans, subtly warning Optimus of the truth by telling him that no other human will ever know. Optimus told him that was is no plan and told Bumblebee to make his goodbye quick. Optimus and the other Autobots were apparently killed when the Xantium was shot down by Starscream.
In truth, Optimus and the others abandoned the Xantium before its destruction and they headed to Chicago to fight the Decepticons with the element of surprise. Optimus arrived just in time to shoot down a Decepticon fighter ship and save Sam, Epps and their team and ordered the Wreckers to kill the pilot. After making a speech about taking the fight to the Decepticons, Sam and Bumblebee took the downed fighter to rescue Carly and succeeded, killing Laserbeak in the process and hooking up with Optimus and the rest of the Autobots afterwards.
Optimus and the other Autobots headed further into the city to open a way for Sam, Epps and their team to make their way to a building where they would attempt to shoot down the Control Pillar. Along the way, Shockwave and his Driller attacked, separating Optimus from his trailer in the struggle. After linking up with the humans in a building, Optimus headed out to retrieve his trailer, needing the weapons and flight gear it contained.
Optimus successfully retrieved his trailer and flew in time to attack the Driller and save the team from death. Optimus shot the Driller multiple times before crashing through its neck, breaking it in half and killing it. Optimus landed on top of a crane where an enraged Shockwave blasted him, causing him to get tangled up in cables. Optimus was spotted by the Wreckers who quickly climbed up to cut him free.
The Wreckers eventually cut Optimus free and he flew back into battle. He went on a killing rampage and slaughtered many decepticons. He then killed Shockwave by cleaving off his left hip and pulling out his eye rather. Seeing an opportunity, Optimus used Shockwave's hand cannon to blast the Control Pillar from the building it was on, temporarily deactivating the space bridge that was bringing Cybertron to Earth. Optimus then challenged an enraged Sentinel to battle and dueled him using an energon battle-axe and an energon sword. Optimus had the upper hand until Sentinel called in the Decepticon fighter ships to attack his former apprentice. Optimus was forced to turn his attention to the Decepticon fighters and shoot them down with his Ion Blaster, allowing Sentinel to flee.
After the fighters were destroyed, Optimus pursued Sentinel, quickly catching up with him at a bridge and re-engaging him. Optimus held his own, until Sentinel cut off his right arm and knocked him down. As Sentinel was about to execute Optimus, he was attacked from behind by Megatron, who had been convinced by Carly that Megatron would be working for Sentinel not with him as Megatron wanted. Taken completely by surprise, Sentinel took a severe beating from Megatron, who tore the elder Prime's helmet off and his chest armor apart. At the same time, after Sam killed Dylan Gould, who had reactivated the space bridge, Bumblebee and Ratchet destroyed the Control Pillar, causing all the Decepticon ships to get sucked up into Cybertron, which collapsed upon itself and was apparently destroyed forever.
Seeing his plans in ruins, Megatron proposed a truce, saying all he wanted was to be in charge again and slyly asked Optimus what he would be without him. Unable to trust Megatron, Optimus responded "Time to find out", and attacked his eternal foe. Even one-armed, Optimus was too much for Megatron. Prime cut his axe into Megatron's upper torso, cleaved off part of his head, lodged his axe into that section, and tore it off, finally killing his enemy. Optimus then turned to Sentinel Prime. The badly injured Sentinel attempted to excuse his actions, but Optimus refused and told Sentinel he didn't betray the Autobots, but rather himself. Despite his former master's plea for mercy, Optimus fired two point blank shots from Megatron's fusion shotgun, executing Sentinel.
Optimus then reunited with the humans and other Autobots and declared that they would never forsake Earth which was their new home with Cybertron now destroyed 
In the aftermath of the battle of Chicago, and realizing the destruction that his race has caused, a small, exclusive band of humans turned against the Autobots. Optimus, realizing his comrades were not safe, ordered all the Autobots on Earth to go into hiding.
Following this betrayal, Optimus himself was attacked by the joint operation of Cemetery Wind and Lockdown in New Mexico. He was severely wounded by a shell fired by the bounty hunter, that almost hit his spark. He fled the skirmish and took the form of a beaten up 1973 Marmon cab-over semi truck. He then hid in a broken down movie theater in a small town in Texas
Sometime after this, an inventor named Cade Yeager and his assistant Lucas Flannery, came to the theatre looking for parts for his inventions. Cade spots the truck and investigates it, as he opens the door piles of spent artillery shells fall out of the cab section. Cade then buys the truck and has it towed back to house.
While repairing the truck in his barn/laboratory with Lucas, Cade made the discovery that it was not made of normal steel, and when he hooks it up to a power source it begins to play Optimus' warning message. Realizing what it was, Cade's daughter Tessa returns to the house. Working on it further, Cade found something lodged in the truck's engine block, after dislodging it he pulled it out to figure out what it is. As he held it, it fired out of the barn and into the family room of the Yeager house. Tessa rushed to the barn to see what was going on. As she got there, the battered truck burst into life and transformed into an enormous robot - Optimus Prime. Badly damaged, dazed and confused, Optimus threatened to kill them, assuming somebody was there to kill him. He lashed out at the three humans, hitting Lucas acrosss the forehead with his rifle. Cade managed to calm him down, and then Optimus explained why he was so defensive. As he did this, one of his ear pieces broke off and crashed onto the floor of Cade's barn. Though his daughter and his friend disagree with him, Cade picked up the ear piece, and vowed to help repair the Autobot leader. As the inventor fashions a shield for it, he reveals the rocket that was lodged in him was inches away from his power source. Optimus explained that it is his Spark, the heart of a Transformer.
Elsewhere, at the HQ of Cemetery Wind, Harold Attinger is given Intel that a truck matching the description of one seen leaving the skirmish sight in New Mexico had been spotted in Texas. He instantly deploys Cemetery wind to the Yeager house. Lockdown is also informed and takes position on a water tower and watches the vents unfold.
Tessa warns her father that what looks like police are coming. Cade hides the Autobot Leader under his Lab. Cemetery Wind then force their way onto the Yeager's property and investigate. Attinger listens in on the mission. Realizing that Cade calls the truck by 'he', he notifies The commander. Getting this intel, the commander pins Tessa to the ground and threaten to shoot her if Cade doesn't tell them where Optimus is. In the Lab, Optimus tries to remain silent as CW soldiers investigate above him. However, he heard what was happening outside and was unable to hide any longer. Prime erupted from the ground and fought past the operatives. He then crashed out of the barn and took on the rest of the troops creating a distraction for the Yeager family and Lucas to escape. Optimus' wounds, if not kills many of the operatives as Lockdown tries to stop him by launching a missile salvo at him, and the escaping humans. Enraged by the failure of the mission, Lockdown began his own pursuit.
As Shane Dyson rescues the Yeager family, Optimus escapes into the nearby town, closely followed by Lockdown, and then the Yeager's. They lose sight of the two transformers. On the roofs of an abandoned factory, Optimus engages Lockdown, even though he is vastly under-powered. He spots his new friends in trouble in the courtyard being chased by Cemetery Wind operatives. He leaps off the roof and purposely lands on one of the pursuing cars, crushing it. After, he reengaged Lockdown. Wounding him enough to make a get away, he went back for his friends as Shane's car had broken down. He managed to save the Yeager's and Shane from a grenade thrown by Lockdown, but Lucas didn't make it to the Autobot. Optimus then sped off into the desert, leaving Lockdown to lick his wounds.
A short time later, Optimus pulled into an abandoned gas station. He dropped off the humans at the gas station and went back to check that they weren't followed. He later assists them in gaining Intel on their new enemy.
Deciding that the time was right, Optimus hailed the remaining Autobots. On his way to the rendezvous point, Optimus scans a new truck form: a Western Star 4900 Phantom Custom Semi-Truck. The process rejuvenates his rusted and battered armor as rust patches and broken parts flake off.
Deep in Monument Valley, Hound and Drift spot him approaching. They all come together as Prime unloads the Humans, Crosshairs being especially happy to see him. He Transform's into his new robot form as his old friend Bumblebee approaches. Hound and Crosshairs aim their weapons at the humans as they do not trust them anymore, but Optimus orders them to stand down as he explains that they saved him The Autobots and their new allies then gather around a fire as Cade tells them about all the information he has discovered on their attackers. They make a plan to infiltrate KSI, the company where they can get more info from.
En route, the Autobots hold up in an abandoned building. Here Cade told Optimus about the trouble he's had bringing up Tessa by himself, and trying to control her. Optimus then explains that he knows exactly what he means as he had the same problem with Bumblebee.
After Bumblebee drops off Cade at the KSI facility in Chicago, the Autobots regroup and watch a live feed of what Cade is filming as he spies on the scientists. When Optimus saw the pictures of what they had done to Ratchet, he raged and slammed his fist into a lamppost. He then storms off and launches a raid against the facility. They speed through the city, Bumblebee acquiring a new alternate as he goes. Bumblebee smashed through the atrium window, and hitched a ride with Drift up to the floor where Cade is being questioned. Optimus and the rest if the Autobots continue to storm through the building to get to the lab. Once there, they destroy every man-made and free Brains. Joshua Joyce tries to stop them. Joyce, after Optimus threatens to exploit what Cemetery Wind and KSI's actions, tells them that they are not needed anymore, as KSI could now make 'newer and improved' versions of them. After this, Optimus tells the Autobots to fall back.
Departing from KSI in disgust, Optimus is attacked by Joyce's creation, Galvatron, which he swiftly realizes is a 'reborn' Megatron. He took out his energon sword, but Galvatron quickly shred it into a stump. Optimus seemed to have the upper hand, but Lockdown came and shot missiles at him. Lockdown captured Optimus and Tessa in his ship, the Knights Temanos. Later, the Autobot squad and the humans sneak aboard the ship before it takes off. Hound and Drift rescue Optimus and some prisoners in a detachable section of Lockdown's ship. Soon after, Optimus, Hound, Crosshairs, and Drift meet up with the human's and Bumblebee. Optimus tells the humans about "the seed" but their attempt to warn Joyce about it and Galvatron's true nature cause all of KSI's drone fleet to activate.
The Autobot's get to Joshua Joyce on a rooftop. One of KSI's drone's shoots missile's at the ship, causing the human's, Hound, and Bubmblebee to fall off. While Bumblebee and Hound attempt to hold off the drones in the city, Optimus attained a Sword and a Shield and released the Dinobots - legendary warriors that transform into versions of Dinosaurs. He engages and defeats Grimlock in a fight to win his allegiance as they fight for their freedom against their creators. Optimus rides Grimlock into the city and fights the KSI drones. After the big battle, Optimus ran over to an underpopulated part of Hong Kong to fight Lockdown. Optimus continued to fight the bounty hunter, when he saw Cade being confronted by Harold Attinger. He killed him with a blast from the blaster attached to his shield. With Optimus distracted, Lockdown attacked him and pushed him against a wall. Lockdown then retrieved Optimus' sword and pushed it through his chest. Cade attacked Lockdown, while Bumblebee, Shane, and Tessa arrive to help him. Shane drove a truck at maximum speed with a cable attached by Tessa to Optimus' sword and the force pulled the sword out of his chest. Optimus caught the sword in midair and pushed the blade through Lockdown's back, killing the bounty hunter, saving Cade, and avenging all those he slaughtered. Optimus then gathered the human's and set off one of Lockdown's grenades to blow up the section and kill the rest of KSI's drones.
Optimus flew the humans to the other Transformers as Bumlebee joins them. Optimus bid farewell to the Dinobots on good terms, informing them that they are now free from anyone's control. Optimus announces that he will venture into space as there is still "a price on his head" placed by the mysterious Creators. He also desires to not only remove the Seed from Earth, but to find out who and what he is as well. Optimus admits to Cade that he did not know if they would ever meet again, but asks his family to think of one of the stars above as his soul. Optimus orders Hound, Drift, Crosshairs, and Bumblebee to guard the Yeager's and their allies in reparation for their own protecting them. Optimus implores them to defend all the humans that can be as he departs Earth.
As he leaves the planet, Optimus sends a message to whoever his Creators are, telling them to leave Earth alone because he was coming... for them  .
Discovering the remnants of Cybertron on a collision course with Earth, Optimus landed on the planet, but was confronted by the Quintessa, who "reprogrammed" Optimus into Nemesis Prime, instructing him to acquire ancient technology hidden on Earth since the time of King Arthur that would allow him to drain Earth's life energy to save Cybertron. Although he killed several Cybertronian Knights while under the Nemesis Prime programming, Bumblebee was able to bring Optimus back to himself, although Cade Yeager- who had become the new wielder of Excalibur- was able to convince the remaining Knights to stand down and not blame Optimus for what he had done as Nemesis. As Cybertron approached, Optimus rallied the remaining Autobots with the Transformers Reaction Force- primarily the members who had once been associated with NEST- to travel back to Cybertron, defeating Quintessa's Infernocons and the assembled Decepticons. With the two planets brought together, Optimus ordered the Autobots to relocate to Cybertron so that they could rebuild their world, although they would retain contact with Earth and help humanity rebuild as well 
Notes & Trivia
- TakaraTomy officially recognizes Optimus Prime's vehicle mode as a Kenworth W900 truck, even though the vehicle used for filming was a modified Peterbilt 379, a different model from a different brand, although both are made by the PACCAR company.
- As part of the hype buildup to the movie release, Optimus Prime made a brief cameo at the 2007 MTV Movie Awards, interacting with host Sarah Silverman. The scene spliced Silverman into pre-existing movie footage, but featured new dialogue recorded for the event by Peter Cullen. Prime heavily hinted that he wanted to present an award, but was rejected for a regular MTV fan.
- Optimus is officially 9.75m (32 feet) tall, weighs 4.3 metric tons, and his primary weapon is an ion blaster. (Considering Optimus' height, however, this weight would seem implausible. However, it is worth noting that a Peterbilt 379 actually does weigh 4.3 metric tons. Make of that what you will.)
- According to a tie-in advertisement for Burger King, Prime likes his Whoppers with no onions, no cheese, and with extra pickles on the side. However, due to a cruel twist of fate, he can never enjoy the sweet taste of beefy victory.
- The Optimus Prime computer generated model consisted of 10,108 individual parts, 1,830,898 polygons, 27,744 rig nodes, and 2336 texture maps. The volume of all pieces combined came to 154 cubic metres (5445 cubic feet).
- Optimus Prime (in truck mode) made an appearance at BotCon 2007, alongside the Sector Seven Mobile Command Unit. He was available for pictures all weekend.
- On July 6, 2009, Optimus Prime, voiced by Peter Cullen, aired on the Late Show with David Letterman. He guest starred to say, "The top ten things that sound cool when spoken by a giant robot".
- 10: "Jergens lotion leaves my hands silky smooth."
- 9: "Do you have these khaki's in size 114?"
- 8: "My perfect night involves a pint of Häagen-Dazs, and season three of 'Sex and the City'."
- 7: "Man, do I love me some taters."
- 6: "It was so hot in Central Park today, I saw a squirrel rubbing sunblock on his nuts."
- 5: "You seemed a little pitchy, dawg."
- 4: "Brody Jenner has added you as a friend on Facebook."
- 3: "Live from New York, it's Saturday Night."
- 2: "My parents wanted me to be a rabbi."
- 1: "All the slammin' shorties in the house say, 'Yeeeah'."
- An innovative Irish company, named RoboSteel, weld scrap steel from various vehicles into film characters and fantasy icons, they created an 8-foot (2.4 m) tall Optimus Prime. It took 2 months to build. It was revealed in the 2011 edition of the Ripley's Believe It or Not! book.
- In the 2012 edition of the book, it was revealed there was another two 8 ft sculptures, these were made in Bangkok, Thailand. Both stand in Ripley's museums, one in Orlando, Florida, and the other in San Antonio, Texas.
- In 2014, Optimus made an appearance in the Nickelodeon 2014 Kids Choice Awards. He did this to try and warn the host (who was Mark Wahlberg) that Nicola Peltz and Jack Reynor were about to slime him, which he prevented by sliming them.
- Transformers: Ghosts of Yesterday
- Bumblebee (Movie)
- Transformers (Movie)
- Transformers: Revenge of the Fallen
- Transformers: Dark of the Moon
- Transformers: Age of Extinction
- Transformers: The Last Knight
- Article at Edmunds.com on some of the vehicles used in the movie
- Robertson, Barbara (2007). Heavy Metal. Computer Graphics, 30(7), 12-17.