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[[quoteright:350:[[Franchise/{{Predator}} http://static.tvtropes.org/pmwiki/pub/images/l22365380_4339.jpg]]]]
[[caption-width-right:350:[[{{Determinator}} The other shoulder has a massive chip on it.]]]]

The AmmunitionBackpack is cool and all, but having to lug both it and your gun may be a hassle. Why not combine them both and get yourself a Backpack Cannon! Yeah, [[AwesomeButImpractical it would probably be really hard to aim]], [[RuleOfCool but come on]].

Compare ShoulderCannon, WeaponizedAnimal, JetPack, and WeaponizedExhaust.


[[folder:Anime & Manga]]
* General Catton in ''Anime/SamuraiPizzaCats'' had a double backpack cannon.
* The Franchise/{{Gundam}} franchise has many examples from pretty much every universe.
** The most iconic examples would be the Guncannon and Guntank from [[Anime/MobileSuitGundam the original series]].
*** The [=RX-78-01=] from ''Gundam: The Origin'' had a backpack-mounted cannon and one [[LaserBlade beam sword]] rack, instead of the traditional pair of saber racks. The [=RX-78-02=], Amuro's Gundam, could have one of the racks replaced by a similar cannon. And of course, this also applies to the ''Origin'' versions of the Guncannon and Guntank.
** The [=GM=] Cannon II and Xamel from ''Anime/MobileSuitGundam0083StardustMemory''. With the Xamel, the weapon's [[{{BFG}} size]] actually makes it easy to mistake it for a ShoulderCannon.
** The Zaku Cannon, introduced in [[AllThereInTheManual Mobile Suit Variations]], was found to be unstable due to its backpack being too heavy and the recoil being too great, though some units were later used by the Earth Federation in ''Anime/MobileSuitZetaGundam'', and by Zeon remnants years later in ''Anime/MobileSuitGundamUnicorn''.
** The [=OZ-07MS=] Tragos from ''Anime/MobileSuitGundamWing'' featured a backpack cannon and a hoverskirt that made it resemble the original Guntank, although both could be detached to allow the Tragos to function as a conventional mobile suit as well. The manga adaptation of the series gave a similar cannon pack to Heavyarms.
** ''Anime/AfterWarGundamX'': The titular Gundam features the backpack-mounted [[WaveMotionGun Satellite Cannon system]]. Its MidSeasonUpgrade, the [[MeaningfulName DoubleX]], naturally has twin cannons.
** The Doppelhorn Striker Pack from ''Anime/MobileSuitGundamSEEDDestiny'' is basically this. It isn't seen too often, but can be attached to any Striker-capable Mobile Suit (such as the standard-issue 105-Dagger). The Integrated Weapons Striker Pack from ''SEED-MSV'' line has this amongst its many weapons.
** Fumina's Powered GM Cardigan from ''Anime/GundamBuildFightersTry'' can swap between beam cannons and [[GatlingGood Gatling guns]], though the latter never appear in the anime itself, only in the [[MerchandiseDriven model kit]] and video games.
* ''Anime/CodeGeass'': The Lancelot Conquista's main weapon is the large [[WaveMotionGun Hadron Blaster]] on its back that folds forward and docks with the [[{{BFG}} VARIS rifle]] in order to fire. And it's so freaking powerful that nothing [[LensmanArmsRace except the Guren SEITEN's upgraded radiant wave surger]] can stop it.
* The eponymous Dougram of ''Anime/FangOfTheSunDougram'' has a gigantic linear cannon mounted on its back -- to fire it, it's pulled down over its left shoulder.

[[folder:Comic Books]]
* ''ComicBook/TheTransformersLastStandOfTheWreckers'':
** Ironfist's lightformer cannon ''is'' his backpack... but he has to take it off to use it.
** The tank mode turret of Ironfist's teammate Guzzle is situated on his back when in robot mode, with the barrel extending far past his head.

[[folder:Films -- Live-Action]]
* From ''Franchise/StarWars'', Boba and Jango Fett's {{Jetpack}}s can fire rockets.

[[folder: {{Literature}}]]
* The ActionPrologue of Creator/RobertAHeinlein’s ''Literature/StarshipTroopers'' features “Y-racks” on the PoweredArmor. They launch pairs of HE bomb a few hundred yards to the left and right. The mission was to just smash stuff, so there was no need to aim.
* ''Literature/TheWarAgainstTheChtorr''. A [[AIIsACrapshoot malfunctioning]] SpiderTank robot orders [=McCarthy=] to PutDownYourGunAndStepAway (unfortunately it's stuck in a loop and won't go to the next stage of verifying his identity). [=McCarthy=] does so, then remote-triggers the rockets in his backpack to provide a distraction while he makes a run for the bigger rocket launcher in his jeep.

[[folder:Tabletop Games]]
* ''TabletopGame/{{Shadowrun}}''. The Ballista Multi-Role Missile Launcher, which is worn as a backpack.
* ''Battlelords of the 23rd Century''. The Cizerack (large quadrupedal catlike aliens) have been known to wear weapon systems mounted on their backs. See a picture [[http://tinyurl.com/34otgrn here]].
* Likewise ''Battle Cattle'' (pic [[http://tinyurl.com/3xryles here]]).
* Most of the power armor in ''{{TabletopGame/Rifts}}'' has this, notably the Glitterboy and its variant armor.
* In ''TabletopGame/{{Warhammer 40000}}'', the Tyranid Biovore is a [[NaturalWeapon living]] Backpack Cannon.
** Tau battlesuit jetpacks have mounting points for either support systems or weapons, with missile launchers most commonly shown in GW's in-house models fitted to the jetpack. The old Broadside models had the best demonstration of this in the franchise; their backpacks were fitted with a pair of railguns, which are [[{{BFG}} at least twice as long as a man is tall]] - one on each shoulder.
* A handful of ''TabletopGame/BattleTech'' [[HumongousMecha Battlemechs]] have this with rear-firing weapons, some being literal backpacks that fire into the rear arc. The more typical 'mounted on the back but firing forward' variety is actually rarer, with the ''Shadow Hawk'' being the most well known, as it is based on the Dougram mentioned above.

* ''Toys/{{BIONICLE}}'': the Toa Hordika's Rhotuka Spinners.

[[folder:Video Games]]
* Mario's F.L.U.D.D. in ''VideoGame/SuperMarioSunshine''
* The Buster Pod from ''VideoGame/CustomRobo Arena'', which was just a cannon mounted on your robo's back.
* ''VideoGame/PokemonBlackAndWhite'': [[WeaponizedAnimal Genesect]], a Pokémon with a mounted cannon on its back, as modified by Team Plasma.
** Blastoise from [[VideoGame/PokemonRedAndBlue Gen I]] is a giant turtle with two water cannons in its shell. Its [[SuperMode Mega Evolution]] introduced in ''VideoGame/PokemonXAndY'' changes it to a single, much larger cannon while giving it two [[ArmCannon arm-mounted cannons]].
* Carol from ''VideoGame/{{Wild ARMs 5}}'' uses a backpack-mounted missile launcher. She can't use it without falling on her ass, but it does pack quite a punch.
* The Taraba ninja from ''VideoGame/{{Shinobido}}'' use these as weapons. [[HighlyVisibleNinja Yup, cannons, right...]]
* [[http://megaman.wikia.com/wiki/Shadow Shadow]] from ''VideoGame/MegaManXCommandMission'' has a "Pulverizer Cannon" on his back. It takes three turns to {{charge|dAttack}}, and like its name suggests, it hurts ''a lot'' on all your characters.
* The Dwarf from ''VideoGame/{{Sacred}}'' has this as a special weapon.
* In ''VideoGame/StarCraftII'', the Thor [[HumongousMecha superheavy siege walker]] and its SuperPrototype Odin both feature a set of four backpack-style guns, described as [[{{BFG}} 330mm high-ex cannon]] (you could fire a smallish ''person'' out of a gun like that). While they are used for single salvoes rather than being an alternate mode shift like the Siege Tank, the mech still has to hunch back and take up a firing stance, rendering it briefly immobile while the weapons are being fired. The results are usually [[ThereIsNoKillLikeOverkill worth the hassle]].
* {{Game Mod}}s for ''{{VideoGame/Tribes}}'' usually add at least one of these. Instead of carrying around a regular backpack, like a shield pack, you can stick a big gun on your shoulder, allowing you to use both your hand weapon and the backpack weapon at the same time.
* The ''VideoGame/DukeNukem3D'' boss "Overlord" has a back-mounted rocket launcher. In fact, the manual says that's about all that's known about it.
* Seeing as the class is a straight-up {{expy}} of [[Franchise/StarWars Boba/Jango Fett]], Bounty Hunters in ''VideoGame/StarWarsTheOldRepublic'' have an attack or two that launches rockets out of their {{jetpack}}.
* In ''VideoGame/KaijuCombat'', the [[AIIsACrapshoot S.C.U.D.]] attached to the {{kaiju}} Katyusha is one that can twist around and serve as a {{jetpack}}.
* In ''VideoGame/DarkVoid'', your jetpack has guns in it. Sort of justified in that they only get used in flight mode when they can be aimed.
* ''VideoGame/SamuraiWarriors'': UsefulNotes/IshikawaGoemon has an actual cannon strapped to his back that he uses in various combo attacks as well as his Musou attack. In the first game he could also use it to blast open certain walls on some levels, revealing hidden loot or shortcuts.
* ''VideoGame/{{Destiny}}'' has Valus Tlu'urn, a Cabal commander who has a giant artillery cannon as his weapon of choice. [[note]]This is due to the Cabal specialising in wars of attrition. Tlu'urn's cannon has recharging arc cells as noted in his [[AllThereintheManual Grimore]] card which means that he is able to fire it indefinitely.[[/note]]

[[folder:Western Animation]]
* The TriggerHappy ManChild known as Metal-Head on ''WesternAnimation/GIJoeARealAmericanHero'' packs a pair of back-mounted guided missile launchers as his primary weapons, which he likes to fire at every opporutnity. He also has [[LegCannon hip mounted missile packs]], but those see less use.

* In 1944 - 45, the German Army was working on what would have been a man-portable anti-aircraft weapon with limited surface-to-air capacity. It took the form of a six-barrelled rocket launcher looking not unlike a Gatling gun but capable of firing six rockets, either singly or in a volley. To make it easier for the operator, it was envisioned that this would be mounted in a modified harness slung over the back, and could be hoisted to the shoulder when it was necessary to fire it. This was another of those weapons that were timed out by the end of the war in 1945; it would have operated on the recoiless rifle principle with backblast angled away from the operator. Not much evidence exists as to whether or not it would have worked.