Fusion cannon

The fusion cannon is Megatron's weapon in many continuity families.

A release of lubricant is quite common when seeing this.

The fusion cannon is Megatron's ultimate weapon. It is attached to his right arm and is devastatingly powerful, as demonstrated by its sudden removal of Ironhide's head. (It's at least as powerful as Fortress Maximus's hands, then.) It strikes fear into the sparks of both the Autobots and the Decepticons, though its actual destructive capacity seems strangely uneven.

Fiction

Generation 1

Marvel Comics continuity

Events from the UK-only comic stories are in italics.

Hey-o!

In order to try to stop an out-of-control Auntie, Megatron began to charge up his fusion cannon by linking up cross-dimensionally from a black hole. Windcharger and Ravage stopped Auntie before the blast was needed, but Megatron wanted to use it on something anyway. Before he got a chance to fire off the accumulated power, Windcharger launched him into the sky. Raiders of the Last Ark

While on a hunt for Optimus Prime, the Predacons betrayed Megatron. Divebomb stole Megatron's fusion cannon and the Predacons left Megatron to fight Optimus Prime with only his Equaliser. Megatron opened a space bridge which pulled both him and Prime to Cybertron where Megatron got a new fusion cannon. The Harder They Die! It is unknown what Divebomb did with the original.

Generation 2

As part of an agreement with Cobra, Megatron's body was rebuilt to resemble a human tank, with his fusion cannon being replaced with a magnetic rail gun.

Generation 1 cartoon

Fusion cannon Megatron's fusion cannon from the Generation 1 cartoon. — 14 KB

Megatron could remove his cannon from his main body. One time, Brawn stole it from him and used it against him. Megatron was not amused. Fire on the Mountain

Fusion cannons are also oddly useful when you just wanna kick your lieutenant for shooting you in the back but don't want to have to walk over to him...yeah, we don't question that. More than Meets the Eye, Part 3 Starscream's Brigade

An attempted coup from Devastator is another matter. The shots kept bouncing off him, and Megatron had to resort to a 5-way fistfight (Starscream, Astrotrain, and Blitzwing were fighting for leadership too) as an alternative. Triple Takeover

IDW comics continuity

The fusion cannon was a gift from Starscream. Megatron Origin issue 4 It's ironic how Megatron decided to pay him back a few hundred thousand years later by blowing a huge hole in his torso. Infiltration issue 6

War for Cybertron

Megatron's precious fires explosive charges into the faces of your enemies. And, oddly enough, it can be used by Optimus.

Carried by: Leaders, Megatron

• Damage: 7
• Range: 9
• Accuracy: 7
• Rate of Fire: 4

Beast Wars cartoon

Megatron loved his fusion cannon so much, he had another fusion cannon installed on the Nemesis. The blast radius from the weapon is massive. Most kickass. It requires a power up time to fire again. Less kickass. Nemesis Part 2

Although not Megatron's, according to Beast Wars, the Ark's cannon was also a fusion cannon. The Agenda (Part III)

Beast Machines

Megatron's personal chariot, Mechatron, comes equipped with a fusion cannon to nullify any accursed Maximal that comes across.

Live-action continuity

Back in the day when he needed both hands to hold/use it.

Megatron's fusion cannon is one of the most powerful weapons known to Transformers. Drawing energy from an unknown interdimensional source, the fusion cannon fires gamma irradiated plasma at a target.

Megatron's cannon is presumably telescopic, as he keeps it stored in his left arm when not in use. Its powerful blast is enough to knock Optimus Prime back three city blocks and requires Megatron to use both arms to steady the aim. Because Megatron is always concerned about collateral damage. That, or making sure he hits. Transformers (2007)

Hey, I can see Starscream's house from here. *fires*

After his resurrection, Megatron still possessed his fusion cannon, but in a more compact form, from which he could now access with his Death-lock pincer, which featured an attached sword. A point blank shot can still send Optimus Prime flying back several yards. Later, after impaling Optimus with the sword, Megatron finished off the job by firing the fusion cannon right through Optimus.

Following his resurrection, Optimus later turned the fusion cannon against Megatron during the final battle in Egypt...by blowing off half of his face, then severing it and part of Megatron's arm off with his own Energon sword. Revenge of the Fallen

It is also mentioned on Ironhide's toy packaging that he also has a fusion cannon; presumably it is the blue glowing laser weapon on his left arm, and it is obviously much smaller than Megatron's.

Animated cartoon

Given time, Starscream may simply develop an immunity to the cannon.

Megatron's iconic cannon served admirably as a cutting torch when Megatron sought to gain access to the Autobots' ship. Transform and Roll Out After Megatron's revival his newly rebuilt fusion cannon proved even more effective against the Autobot ship, knocking it clean out of the sky in under a minute with some help from Lugnut and Blitzwing. It also has a lens... sometimes. Megatron Rising - Part 2 It was instrumental in repeatedly killing the newly-immortal Starscream, Mission Accomplished and used in the capture of Bulkhead. A Bridge Too Close, Part I

Eventually, it (as well as his swords; this was not seen, but his "weapons", plural, were referred to) was removed when he was captured by Omega Supreme's internal defenses. Optimus Prime discovered, painfully, that Megatron was not as weak without it as Optimus had hoped. TransWarped

Notably Megatron, despite always hitting Starscream, rarely manages to aim correctly when facing the Autobots. The writers were likely reluctant to have half the cast atomized in the space of five seconds, but to be fair, Starscream was at point blank range for nearly every shot.

Megatron's fusion cannon is eventually destroyed by the hand of Optimus Prime with Ultra Magnus's Magnus Hammer. Endgame, Part II

Notes

• The deep percussive note at the beginning of the iconic fusion cannon sound effect (used throughout G1 and Animated) is an old "stock" sound used frequently in American animation, most notably within Hanna-Barbera's Scooby Doo where it was used to signify cast members or objects falling on the ground, running into walls, etc.