Canon History

taken from wiki

Megatron is an iconic Transformer alongside his rival, Optimus Prime, primarily because of his large exposure in the comics and television series as well as his function as the leader of the villainous Decepticons, opposite the heroic Autobots.

Megatron is very powerful and utterly ruthless. His imposing robot form is dominated by his primary weapon - his arm-mounted fusion cannon, capable of leveling a city block in one blast. He can also sub-dimensionally link the weapon to a black hole, generating even more powerful antimatter blasts (capable of destroying a small planetary body). However, this ability is almost never used, as it leaves him extremely weak and vulnerable.  He has a secondary weapon barrel mounted on his back, and can retract and replace his right hand with an energy flail. He can fire electrical blasts from his hands, laser blasts from his eyes on at least one occasion and can reprogram computers with a port in his head.

There have been several interpretations of his character; some see Megatron as a strategic leader who calls the shots from afar, whilst others see him as a tactical battlefield commander who leads by brutal example. Unlike many other villains in popular fiction, Megatron was not generally depicted as overly chaotic or insane. He was highly aggressive and a megalomaniac, but there was usually a consistent rationale behind his actions, albeit that Megatron was often the only one who could perceive this.

There have been some sparing occasions where Megatron displays a personal sense of fair play and even honor, a complexity that is most evident in his complicated relationship with Optimus Prime. There is an unspoken mutual respect between the two leaders, born of each knowing the other better than anyone else. Megatron at times seems to derive enjoyment from the perpetual conflict that exists between them — the pleasure of ending the life of Optimus Prime will be Megatron's and Megatron's alone, and to ensure this, he has aided Prime in the face of greater threats, such as the Combaticons or Jhiaxus's second generation Cybertronians. In instances such as these, the two have come to face the fact that were it not for their diametrically opposed ideology and views, in another life, the two could be comrades — a fact that Optimus Prime views as a tragedy, but which provides Megatron with amusement.

According to his original tech spec, Megatron has no known weaknesses. This does not, however, spare him from defeat at the hands of his enemies. For all his famed battle prowess and tactical ability, Megatron's complacent overconfidence often causes him to overlook some vital strategic detail. Also, he has a bad habit of ordering a retreat at the first sign that the tables have turned against his side in battle (even when the Decepticons still maintain the overall strategic advantage). Another factor that could contribute to his losses is his rough relationship with some of his own troops (most specifically Starscream). Despite his lust for galactic domination, one of Megatron's key priorities remains the safety and health of Cybertron; and from his viewpoint, the best way to accomplish that is for him to conquer it.

Cracktran History

(movie verse form)

Stuck at the bottom of the ocean (with Blackout's hand fused to his aft), Megatron continued to plot against those who dared defy him.  The hole in his chest was filled by a family of jellyfish (later removed by Hook) and eventually he was freed from his watery prison by Thundercracker, Frenzy, Barricade, and handful of others he fails to recall.

However, the afthanding he was given in Mission City, and his stint on the bottom of the ocean, left him impaired.  Prone to serious processor glitches (binary and musical numbers) and moments of complete irrationality, many of his crew began to doubt his ability to lead.  Apparently, the idea of setting up base in Disneyland didn’t go over so well.  This eventually led to a mass exodus of Deceptions, leaving Megatron with only a handful of loyal followers.

But the defection of his troops wasn't the worst of what was to come.  The former High Lord Protector was finally forced to face a painful part of his past--in the form of Optimus Prime.  Once romantically involved on Cybertron, the two had a bitter, bitter, split that resulted in Megatron making the decision to end the current civilization of Cybertron and begin it anew.  Too bad he got a bit carried away.  So began a long and violent war, fueled by a scorned lover's hate.

On Earth, he and Prime met and fought during one of Frenzy's raves.  Using an underhanded tactic (aka planting one on Megs), Prime ended the battle and Megatron decided to hear his former beau out.  What was supposed to be a Coming to Jesus talk ended in a life long commitment.  In a heat of passion, they bonded with one another, thus ending the war.  One would think this would make everyone happy, but nooooooooo.  There were more defections, a lot of arguments, and a whole bunch of drama.  Such is life on Earth.

With the war over, Megatron finds himself easily bored.  With nothing to destroy, he finds other ways to spend his time, like shacking up with Prime in their quarters, cannonballing into Old Faithful, making Amazon.com lists, terrorizing Starscream, drinking copious amounts of Blackout's high-grade, getting kidnapped by Sector Seven agents or Quintessons, watching movies with Ironhide, etc.  Oh, and he collects duckies.  Lots of them.  Like an entire closet full, plus the one outside the base. (see photo for reference).

Regardless of his idleness, he is still a force to be reckoned with.  When he is focused on an enemy, he is as deadly and ruthless as ever—perhaps even more so now that he feels he has to redeem himself as High Lord Protector of his race.  He’s constantly at war with his instinctive need to destroy—but that is tempered by his tie to Prime...most of the time.  If that doesn’t work, Hook just beeps his nose with a ducky until all is right with the world again.

When it’s all said and done, what Megatron really wants is a long vacation.  Preferably at Disneyland, where Prime has promised to buy him a balloon.

And yes, he recently learned that a threesome can be a lot of fun, but only when it involves himself, Prime, and Thundercracker.  He's not too keen on the idea of anyone else joining in (ie: touching Prime).  He's funny that way (mine, he growls).  He was also convinced to get himself a holo form, two actually, which is endless frustration amusement for those around him.  He doesn't seem to have too much trouble with his male holo, but has a hard time understanding the concept of clothes when it comes to the female version.  He blames it on the endless wardrobe choices in the programming and his real lack of giving a damn about anything regarding human culture.  Prime finally had a talk with him and at least now he remembers to put a bra and panties on her.