He's also good friends with Twilight Sparkle.
In the live films
The character of Optimus Prime first appears in Transformers (film) as the leader of the Autobots in the search for the Allspark. After arriving and scanning a Peterbilt truck, Optimus greeted Sam Witwicky and Mikaela Banes, introducing his men and explaining why they had come to Earth. They escorted the humans back to Sam's house to retrieve the pair of glasses that would lead them the Allspark. When Sam and Mikaela were captured by a Sector 7 agent named Simmons, Optimus intercepted their car and surrounded the Sector 7 agents, curious that Simmons was not afraid or surprised by their appearance. When backup arrived, Optimus took the teens on his back and ran, taking cover under a bridge. Though Sam, Mikaela, and Bumblebee were captured, Optimus retrieved the glasses and prepared to lead his other men to get the Allspark, pointing out that, if it came to it, he would sacrifice himself by shoving the cube into his chest to prevent he Decepticons from getting control of the Allspark. When they discovered Bumblebee and the humans were free and being escorted by the military with the Allspark, Optimus joined their convoy. Along the way they, are attacked by Bonecrusher. Optimus engages him, killing him by using his Energon blade. Arriving in the city, he briefly confronted Megatron, but was left stunned. When he recovered, he rescued Sam as he was falling from a building and warned him that if he could not defeat Megatron before going into battle, he needed to place the Allspark in his chest. Optimus is nearly defeated by Megatron before Sam kills the Decepticon by ramming the Allspark into his chest. Optimus is grateful to Sam for saving him, and he and the other surviving Autobots decide to remain on Earth since Cybertron cannot be restored without the cube. The film ends with Optimus sending out a deep-space signal, inviting other Autobots to join them on Earth.
Optimus Prime's character returns in Transformers: Revenge of the Fallen. He leads the Autobots as part of NEST in seeking and destroying remaining Decepticons on Earth. At the beginning of the film, the massive Decepticon Demolishor is rampaging through Shanghai, China, and Optimus parachutes out of a plane to take him on. Before he is killed, Demolishor tells them that the Earth is "not theirs to rule" and that "the Fallen shall rise again". At the NEST base, Optimus tells Theodore Galloway that they do not know what The Fallen is and that if they are asked to leave Earth, the Autobots will comply. When the remaining Allspark shard is stolen, Optimus asks Sam for his help in convincing the Earth's leaders to allow the Autobots to stay, but Sam refuses. When Megatron is resurrected and Sam, Mikaela and Leo Spits are kidnapped, Optimus and Bumblebee attack the Decepticons holding them. Optimus fights Megatron, Starscream, and Grindor on his own to protect Sam in a forest. Though he manages to kill Grindor and rip Starscream's arm off, Optimus is ultimately killed by Megatron. His last words were for Sam to run. His body is taken to a military base where Galloway orders the Autobots to bring his body back to Diego Garcia. Meanwhile, Sam hears from Jetfire that "The Fallen" is an ancient Prime and that only a Prime could kill him. He also said that the Matrix of Leadership may be able to revive him. After a long battle with the Decepticons in Egypt, Sam resurrects Optimus using the Matrix, but it is subsequently stolen by The Fallen. Because Optimus is still weak, Jetfire offers to sacrifice himself to help. Ratchet and Jolt convert parts from Jetfire into a jet mode for Optimus. Optimus flies over to the pyramids and destroys the Sun Harvester. After severely damaging Megatron, he kills The Fallen, forcing Megatron and Starscream to retreat. At the end of the film, he thanks Sam for reviving him and again transmits a message to space, hoping to find more Autobots.
Optimus appears again in the 2011 film Transformers: Dark of the Moon. Optimus receives his own armory consisting of weapons and flight tech that transforms into a trailer for him to carry in vehicular form. After assisting NEST operatives in fighting Shockwave at Chernobyl, Optimus learns that the humans have concealed the discovery of a Cybertronian ship on the moon. He and Ratchet go to investigate the Ark, where they recover Sentinel Prime, Optimus's predecessor and mentor. Optimus returns him to life using the Matrix of Leadership back on Earth, explaining how they lost the war and Cybertron has become a barren wasteland. Later Optimus shows Sentinel the natural beauty of Earth, and takes the opportunity to offer him the Matrix, but was allowed to keep it. Sentinel later betrayed the Autobots, having formed an alliance with the Decepticons because he wants to restore life to Cybertron. Optimus attempted to reason with Sentinel, but failed as several Decepticons came through a space bridge. After Sentinel Prime insisted that the humans expel the Autobots from Earth, the Wreckers prepare the Autobot ship Xantium for flight. Sam attempts to find out what their counter-attack plan is, but Optimus states they have none, and that Earth's fight is their own. During the departure, the Autobots escape in the first booster stage and return to Earth before Starscream destroys the ship. Arriving in Chicago, Optimus shoots down a Decepticon fighter as he tells Sam and Epps that he never expected the Decepticons to keep their word and that they are going to fight back. Optimus loses his trailer when Shockwave and his Driller arrive. He manages to retrieve it later and uses it as a flight pack, decapitating the Driller's main head. During the battle, Optimus got caught in exposed wires and the Wreckers helped free him. Flying down onto the main battlefield, he abandoned his flight pack and used the momentum to attack and kill many Decepticons before he finally killed Shockwave. After using Shockwave's cannon to disable the control pillar for the space bridge, Optimus fights Sentinel Prime. Optimus Prime's right arm is cut off and Sentinel is about to end Optimus's life when Megatron intervenes and attacks Sentinel. After defeating Sentinel Prime, Megatron proposes a truce, but, instead, Optimus slices his head off, killing the Decepticon leader. Optimus Prime then grabs Megatron's shotgun and prepares to execute Sentinel, who pleads for his life, saying that he betrayed Optimus just because he wanted to save their race. Optimus executes him anyway, replying that Sentinel betrayed himself. With the Decepticons defeated and the war finally over, Optimus and the Autobots accept Earth as their true home.
In Transformers: Age of Extinction
In the aftermath of the battle of Chicago, and realizing the destruction that his race has caused, the humans of Earth turned against the Autobots, realizing his comrades were not safe, he ordered all the Autobots on Earth 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. He fled the skirmish and took the form of a beaten up Flat-nose semi truck. He then hid in a broken down movie theatre 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 makes the discovery that it's not made of normal steal, and when he hooks it up to a power source it begins to play Optimus' warning message. Realizing what it is, Cade's daughter Tessa returns to the house. Working on it further, Cade finds something lodged in the trucks engine block, after dislodging it he pulls it out to figure out what it is, as he holds it, fires out of the barn and into the family room of the Yeager house. Tessa rushes to the barn to see what's going on, as she gets there the battered truck burst into life and transforms into the Autobot leader. Badly damaged, dazed and confused, Optimus lashes out at the 3 humans, hitting Lucas with his rifle. Cade manages to calm him down, Optimus then explains why he's in such a bad way, as he does this one of his ear pieces breaks off and crashes onto the floor of Cade's barn. Though his daughter and his friend disagree with him, Cade begins to try and repair Optimus as best he can. As the inventor fashions a shield for it, He reveals the the rocket that was lodged in him was inches away from his power source, Optimus explains that this 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 a short distance away. He watches events 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 can hear what's going on outside and unable to hide any longer, he erupts from the ground and fights past the operatives. He then leaps out of the barn and takes 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 the escaping humans and Autobot. Enraged by the failure of the mission, he begins his own pursuit.
As Shane Dyson rescues the Yeager family, Optimus escapes into the near by town, closely followed by Lockdown, and then the Yeagers. 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 of the roof and purposely lands on one of the pursuing cars, crushing it. After this he reengages Lockdown. Wounding him enough to make a get away, he goes back for his friends as Shane's car has been broken down, he manages to save the Yeagers and Shane from a grenade thrown by Lockdown but Lucas was killed. Optimus then sped off into the desert, leaving Lockdown to lick his wounds.
A short time later, Optimus pulls into an abandoned gas station. He drops off the humans and goes back to check that they weren't followed. He later assists them in gaining intel on their new enemy.
Deciding the time was right Optimus hails the remaining Autobots. On his way to the rendezvous point, Optimus scans a new truck form. 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 Transforms into his new robot form as his old friend Bumblebee approaches. Hound and Crosshairs aim they're weapons at the humans as they do not trust them anymore, but Optimus orders them to stand down as he explains that they owe them. The Autobots and their new allies then gather around a fire as Cade tells them about all the infomation he has discovered. They make a plan to infiltrate KSI.
En-route, the Autobots hold up in an abandoned building. Here Cade talks to him 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 sees the pictures of what they have done to Ratchet, he goes mad and slams 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 smashes through the atrium window, and hitches a ride with drift up to the floor where the captured 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 everything and free Brains. Joshua Joyce tries to stop them. He tells them that they are not needed anymore. Hearing 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, created when Brains was forced to help KSI access the databanks in Megatron's damaged head. During the fight, Optimus and Tessa are captured by Lockdown, who is revealed to be an agent of the creators of the Transformer race, sent to claim Optimus and the ancient Dinobots- early versions of the Transformers- for the creators. The other Autobots manage to rescue the prisoners in a detachable section of Lockdown's ship, but their attempt to warn Joyce about Galvatron's true nature cause all of KSI's drone fleet to activate.
While Bumblebee and Hound attempt to hold off the drones, Optimus releases the Dinobots, defeating Grimlock in a fight to win his allegiance as they fight for their freedom against their creators. As the Decepticons are overpowered by the Dinobots, Lockdown attacks Optimus, but Cade is able to distract Lockdown long enough for Optimus to gain the advantage and defeat him.
Optimus regroups with the Dinobots, Autobots and their other human allies. Optimus bids 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 he still has 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 the Autobots to guard the Yeagers 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 to leave Earth alone because he is coming for them.
- Optimus Prime is also good friends with Thomas and Twilight Sparkle.
- Optimus Prime will meet Thomas, Twilight Sparkle and their friends in Thomas and Twilight Sparkle's adventures of Transformers.
- Optimus will guest star in Thomas and Twilight Sparkle find Atlantis The Lost Empire.
- In many adventures, Optimus sends a message out into space at the end of most of them.
- Optimus will meet Code Red and be one of the Autobots to respond to the Indominus Rex situation in Pooh's Adventures of The Myth of Burton.
- Optimus Prime will meet Sora and his friends in Sora's Adventures of Transformers.