
Megatron is the main antagonist of the live actionTransformers movie and the secondary antagonist of its four sequels, being based off his original incarnation with the same name. Formerly the Lord High Protector of Cybertron, Megatron's already violent mind went into action under the influence of his master and attempted galactic conquest before the heroic Autobots waged war on his newly formed Decepticon military.
In all three films, he is portrayed by Hugo Weaving. In the games, however, iconic voice actor Frank Welker reprises his role as him.
History
Transformers
Megatron appeared as the main antagonist in the live-action Transformers film.
In the live-action film, Megatron was the cause of Cybertron's destruction when Decepticons and Autobots have started a war that has destroyed much of Cybertron. The All Spark was fought over by both sides until it was lost in space, then landed on Earth at an unknown time, then humans found the cube and a human organization that investigates extraterrestrials called Sector 7 kept the All Spark in its' base for over a century. Megatron followed the All Spark to Earth, but crash landed in the Arctic where Captain Archibald Witwicky and his crew of men were. Captain Witwicky fell in an arctic hole and found Megatron who was frozen. But when Captain Witwicky touched the tip of Megatron's fingers, he also re-activated Megatron's navigation system, and Megatron (still frozen) flashed his eyes that imprinted the All Spark's location onto Captain Witwicky's eye glasses. The Decepticons and Autobots searched for the eye glasses when they found it on the web site eBay. Sector 7 took Megatron who was still frozen to the same base where the All Spark was.
When Decepticons Frenzy and Starscream freed him, he rose again and went into Mission City fighting the Autobots. Decepticons Blackout, Brawl, and Starscream are also in battle against Autobots Optimus Prime, Bumblebee, Ironhide, Ratchet, and Jazz. He kills Autobot Jazz by ripping him in half, then Optimus Prime came in and battles Megatron. At one point, there is actually a conversation where Optimus Prime and Megatron fight over their opinion of the human race. Megatron believes humans don't deserve to live while
Optimus believes that humans deserve to choose for themselves. Hearing this, Megatron orders Optimus to join the human race in extinction.
Optimus could not defeat him and for a period of time, Megatron was able to chase Sam Witwicky when he carried the All Spark that gotten much smaller because of Autobot Bumblebee touching it. Megatron stalked him through a tall building, with Starscream destroying the helicopter that was supposed to carry Sam. Megatron nearly kills Sam Witwicky by knocking him off the building but Optimus rescues him. Blackout was about to aid Megatron in battle with Optimus, but was destroyed by the US Military. The Air Force then blast several missiles and human soldiers use guns to shoot bullets at Megatron. Despite suffering damage, Megatron could not be killed by human weaponry, with the human race determined to destroy him fail. Then, Sam Witwicky pushes the All Spark into Megatron's chest, and the Decepticon is finally destroyed. The war ends with Megatron, Blackout, and Brawl dumped into the Laurentian Abyss while Autobots and humans unite.
Transformers: Revenge of the Fallen

In the sequel Transformers: Revenge Of the Fallen, Megatron was resurrected by the Constructicons Long Haul, Rampage & Mixmaster and Ravage using a stolen piece of the All Spark. He is not the main antagonist in the film but is the secondary antagonist (the main antagonist is The Fallen, Megatron's master and the true leader and founder of the Decepticons). It actually turns out that the reason why Megatron became so ruthless and power-hungry was because the founder of Decepticon corrupted him into serving him, thus making the Fallen responsible for the war between the Decepticons and Autobots that destroyed much of Cybertron. Megatron is not as strong as in Revenge of the Fallen as he was in the 2007 movie because his original body parts are unusable since he was killed off by the AllSpark before being brought back to life. Instead, his original body parts are replaced by a weak Decepticon, Scrapmetal (called "ze little one" by The Doctor). Upon being resurrected, Megatron then orders Grindor to capture Sam as the human had some important information from another piece of the All Spark. Grindor then captures Sam and his friends and brings them to an abandoned factory, Megatron then starts to interrogate Sam until Optimus and Bumblebee arrived to save Sam and his friends. Megatron then chased Optimus and Sam until he caught up with them, Megatron and Optimus battled each other, at first Optimus gained the upper hand unlike in the first movie where he could not do anything to harm Megatron. Megatron called upon Starscream and Grindor. Despite being outnumbered, the Autobot leader managed to fight all three Decepticons, severing Starscream's right arm and killing Grindor by ripping his head apart. Megatron then caught Optimus off-guard and stabbed him in his spark chamber, killing the Autobot leader. He and Starscream then retreated when Autobot reinforcements arrived.
With Optimus now dead, Megatron was quite pleased until Starscream informed him that they lost Sam. Furious with his lieutenant's failure to capture a single "insect" before brutally beating his lieutenant Starscream then replied that there were seven billion insects on the planet and Sam was just one among them and that he could be anywhere. Megatron then decides to force the humans into finding Sam for the Decepticons and also decides to come out of hiding and reveal their existence to the Earth. He then broadcasts a message from the Fallen by using the Empire State Building's radio tower. He and the Decepticons then head to Egypt where the Sun harvester, a machine used to harvest energon out of suns hidden in a one of the pyramids of Giza. Starscream then informs Megatron that Autobot's human allies have brought Prime's body. Megatron then realizes that Sam has the Matrix of Leadership and can revive Optimus with it. Megatron tells Starscream that they cannot let Sam get to Optimus and then he order the Decepticons to begin their assault.
Megatron then takes part in the battle against the Autobots and then he nearly killed Sam but then he was suppressed by human firepower and was forced to retreat. Megatron is then seen on top of the pyramid when a revived Optimus (with parts given to him by Jetfire) destroys the Sun Harvester and knocks Megatron and the Fallen off the pyramid. Megatron then battles Optimus but then gets half of his face blown by his own fusion cannon and then Optimus severs Megatron's right arm with his energon swords and using his afterburners to send Megatron hurling through the ruins. Megatron, being severely damaged, call outs to Starscream for help and then watches helplessly as the Fallen is killed by Optimus. Seeing this, Starscream suggests that he and Megatron retreat, to which Megatron agrees, vowing that "This isn't over".
Transformers: Dark of the Moon

Megatron returns and is the secondary antagonist of the film.
Greatly weakened by the injuries he sustained fighting Optimus Prime in Egypt, Megatron was revealed in Transformers: Dark of the Moon to be hiding in the African Savanah along with Starscream, Soundwave, Igor, andLaserbeak. Unable to challenge Optimus directly, Megatron arranged for Shockwave to reveal to the Autobots the location of the lost Autobot vessel the Ark and it's pilot, Optimus' mentor and former Autobot leader Sentinel Prime, on Earth's moon. Unknown to Optimus, during the war on Cybertron Megatron had convinced Sentinel to betray the Autobots under the pretense of ending the war for the sake of preserving their homeworld, should his plan with The Fallen failed. Once Sentinel's treachery was revealed however, Megatron himself was betrayed by his alleged ally as Sentinel overthrew him and siezed command of the Decepticons for himself.
During the Decepticon attack on Chicago at the film's climax, Sam's girlfriend Carly pointed out to Megatron that as long as Sentinel was around, he would be less than nothing (said that Megatron that in the end, he will became the Sentinel's b*tch). There's a possibility that it's also means Sentinel will killed him later and reduced him into scrapheap as well. This goaded Megatron into attacking Sentinel just as he was about to finish off Optimus. With Sentinel incapacitated, Megatron proposed a truce with Optimus, arguing that they would be nothing without each other. Optimus however found no agreement in the the truce and promptly decapitated Megatron with his energon battle axe.
However, in the film's novelization, after Sentinel Prime is killed, he instead asks Optimus to let him leave Earth and return to Cybertron's remains, saying that he is tired of the war. Optimus is initially skeptical, but after Megatron offers to let Optimus shoot him with Sentinel Prime's gun as an alternative, he allows the badly damaged Decepticon to leave, ending the war.
Age of Extinction

Megatron is the secondary antagonist of Age of Extinction, and is now known as Galvatron.
KSI salvages Megatron's severed head, where CEO Joshua Joyce having them using it to create a new Transformer that intended to resemble Optimus Prime. However unknown to any of the humans, their tampering re-activated Megatron's spark within, and he began to influence the humans to create and entire army of Transformers so he would eventually hack them and rebuild his Decepticon army. He also learned of an ancient Cybertronian weapon called a "seed" which could cyberform an entire city on it's own which he desired to replicate into more but found himself under human control and renamed Galvatron.
Humans' control over himself didn't last long, however, as Megatron later freed himself permanently, but not before reformat other artificial transformers so they became his new army. However, the new Decepticon army was destroyed and Galvatron was forced to retreat with his remainning minions. He took over Lockdown's spaceship and his remainning army and claimed that he and Optimus will meet again one day.
Transformers: The Last Knight
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