Megatron was a young mathematician who lectured at a university on Cybertron. However, he noticed a disturbing trend in the numbers: civil war was certain! His colleagues just called him crazy and laughed it off, but when the maniacal Optimus Prime and his evil army of Autobots took over Cybertron, Megatron had been waiting in the underground, forming a resistance movement to take back Cybertron and keep the Autobots from conquering the universe and plundering it, as they had done to Cybertron.
There were those who opposed the tyranny of Optimus Prime's merciless Autobots, but they were scattered. But there would come a leader, and Megatron emerged from the city of Polyhex to unite them. After retaking some of Cybertron, Megatron pushed the odds in his favor by inventing the art of transformation and renaming his forces "Decepticons." However, Optimus Prime was able to duplicate this technology, and intended to use it to conquer other worlds.
As Optimus Prime built his Ark for this purpose, Megatron and his inner circle planned to derail Prime's attempts at expansion. During a critical moment, the body of what appeared to be one of Optimus Prime's former lieutenants, Cliffjumper, was discovered by them and brought into their Polyhex stronghold. It was discovered that Cliffjumper had travelled from another universe which darkly mirrored their own. After some misgivings, Cliffjumper agreed to aid them in their assault on the Ark and lent the technology from his glass gas towards the cause. On the battlefield, Prime was enraged that Cliffjumper had doublecrossed him, and Megatron took the shot that was meant for the strange traveler. Cliffjumper was finally convinced of where he stood and backed Megatron whole-heartedly, and after destroying the Ark and its launching platform, Megatron critically wounded Prime and called his forces into retreat.
He defends the Arch-Ayr fuel dump from an Autobot attack. He later sends several of his troops to capture and reprogram the rogue Dinobots built by the mad Autobot scientist Wheeljack.
Megatron is captured by the Autobot Targetmasters, but was freed thanks to help by the Predacons and Whisper. When confronted by Optimus Prime he attempts to use the Autobot Targetmaster Nightstick to shoot the Autobot leader, but Nightstick takes control of Megatron's arm. Megatron then tricks Optimus into using Megatron's own weapon to cut Megatron's hand off, freeing him from Nightstick. Megatron misses the launching of the Decepticon ship Nemesis, which is taken over by Starscream to counter Autobot ship Ark.
Megatron greets a Quintesson and the dimensional travelers Breakaway, Topspin Skyfall and Landquake after their escape from the Autobot combiner Computron. Megatron introduces the travelers to Heatwave, but then is shot by the traitor Cyclonus, who is working for Alpha Trion. The travelers try to combine their powers with Heatwave to return Megatron to life, but instead have a vision of Skyfall and are combined into Nexus Prime. Nexus Prime resurrects Megatron as Galvatron.
- Megatron & Rodimus (Convention Souvenir 3-Pack, 2008)
- Accessories: Tank-cannon, missile, sword-blade
- Megatron is a redeco and retool of Ultra-class Energon Megatron, with another color scheme and a new head mold based on an early character model for Generation One Megatron (see below). He comes with Rodimus and Rampage as a bagged set, limited to 1100 pieces.
- Megatron transforms into a silver and black Cybertronic jet with red accents and blue translucents. Included is a small tank (which is originally a representation of Armada Megatron's tank form, and sort-of a homage of Megazarak.), which can plug onto the top of the vehicle mode and can also fire missiles out of its spring-loaded main gun. Hyper Mode can be activated by tugging his transparent wing tips outward, which extends the blue sections, raises the upper gray parts of his wings in an "X-wing" configuration, and deploys the red weapons underneath. In robot mode, the small tank accessory can be attached to either of his arms as a cannon, or it can be flipped around and have a sword attached to the rear of its turret. Like most convention exclusives, the electronics from this accessory have been stripped out to keep costs down.
- Galvatron & Thundercracker (Convention Souvenir 2-Pack, 2011)
- Accessories: 2x missiles, Cyber-key
- Galvatron is a redeco and retool of Voyager class Cybertron Evac, with a more heroic color scheme. He comes with Thundercraker as a bagged set, limited to 1800 pieces.
- Galvatron transformers into a purple and silver Eurocopter Dauphin rescue helicopter with red accents. His rotor blades spin using a geared push-button, which becomes a spinning-blade weapon mounted on his robot mode's left arm. He has an adjustable tow-hook on a string, which retracts with the push of a button: this gimmick ends up on his right robot-mode arm. Inserting a Cyber Planet Key into his back end (backpack in robot mode) swings around a pair of spring-loaded missile launchers. Like most convention exclusives, the electronics from this accessory have been stripped out to keep costs down.
- Megatron's head design is based on the early G1 Megatron character model seen in the first Transformers commercial, early issues of the Marvel Comics, and Megatron's Marvel Transformers Universe profile. Likewise, the helmet colors are derived from the Marvel Comics as well, featuring a black helmet on a silver face. The head was designed by Dan Khanna.
- Megatron using math to predict future trends is based on psychohistory from Isaac Asimov's Foundation series of novels,  but if we wanted to be cynical about it, we'd probably point out that it's more likely inspired by its recent importance in Marvel's Fantastic Four Civil War crossover.