The Ork Kill Tanks are a family of Super Heavy Tanks developed by the Orks to compete with the likes of the Imperial Malcadors in both killiness and dakka. Each of these vehicles are surprisingly resilient, and have specialized weaponry designed to either shred infantry like paper or demolish fortifications like they aren't even there. They are split between the Kill Blasta, Kill Bursta and Kill Krusha.
The various dakka
The Kill Blasta is the one specializing in anti-infantry warfare, armed with an imposing array of Rattler Kannons, Dakkaguns, rapid-firing repeeder-kannons and Shootas of all sizes, collectively referred to as the Giga Shoota. These tanks are casemate designs, like the Kill Bursta, probably due to the need to feed a staggering rate of ammunition into the array of automatic weapons which forms the main armament. Unfortunately this means that the driver must physically turn the entire vehicle to fire at a different angle.
Kill Blastas are known to be quite formidable against Monstrous Creatures despite its overall lack of armor piercing armament. It is the Giga Shoota, which consumes ammunition like a Neckbeard with his Meatbread; chewing the natural armour of these creatures until there is nothing left but tenderized minced-meat and bloodied organs. Unfortunately due to the way its weapons are placed, it also means that ironically, Kill Blastas are actually really bad against fast and nimble infantry that can attack on its blind spots and hack it to death. This means that while armies dependent on mass of infantry like Tyranids will suffer with critical existence failure, the Eldar whose army consists of extremely fast and nimble troops can run circles around it. God forbid if the Kill Blasta has to face a group of Fire Dragons. To put it short, against Tyranids, Orks, Space Marines and Chaos Space Marines, the Kill Blasta shines, as its horrendous fire-rate can reduce an entire 'Nid horde to mush and continuously suppress an Astartes chapter (who are too limited in number and too specialized in high-performance infantry warfare) into submission. Against armies that can field as many tanks and artillery as they can Flak-armored infantrymen, are tough enough to find the Giga Shoota as a minor annoyance or fast enough to avoid its line of sight by jumping everywhere, the Kill Blasta starts to fold itself like paper. It is certainly a tank that has to be matching up against the right force.
The Kill Bursta is the one that specializes in anti-everything-else warfare. Foregoing the idea of "more is better" in favor of "bigger is better," Kill Burstas mount a single huge hull-mounted howitzer capable of destroying tanks, bunkers, office buildings, city blocks, or fortified castles with ease. Since Orks don't really have much in the way of standardization, this enormous gun comes in two flavors: the Belly Gun and the Bursta Kannon.
The Bursta Kannon fires a shell the size of a compact car, and so needs to be very close to its target or else the shell will simply fall out of the air before impact; the Orks don't care much though, because the resulting explosion is so almighty that it will rip apart quite possibly any target foolish enough to wander within range (even Titans!). The alternative Belly Gun is an old Ork favorite, designed for use in Gargants and large Stompas; the Belly Gun chucks a huge pile of scrap metal, rubble, explosives and sometimes feces a considerable distance at whatever the driver can be bothered to point it at. Since each shot is aggregated by a horde of Grot "gun-lowdaz" from whatever spare parts and odds and ends that reside in or around the vehicle mounting the Belly Gun, and the results of any given shot may vary. Sometimes the Grots have an ammunition dumps' worth of looted explosives and metal bits to load in the gun, and when the trigger is pulled a whole regiment of foes are suddenly erased from existence. Other times the Grots can't be bothered to find enough tat before the inevitably over-eager gunner pulls the trigger again, and the Belly Gun merely hurls a misplaced aircraft bomb or human-sized chunk of concrete at the enemy, and nothing more. Due to the unthinkable recoil of either cannon, the casemate design returns for the Kill Bursta,and the static Kannon means the entire vehicle must move in order to aim and fire a single shot.
Fun fact: the Kill Bursta is loosely based on the Sturmtiger Assault Gun, a Tiger 1 conversion that mounted a 380mm Rocket Launcher as a building-demolishing howitzer. The Rocket Launcher was adapted from a Depth-Charge Launcher. Now dat's right Orky.
Unlike its previous brethren, the Kill Krusha is a fully front-line battle tank with a semi-turreted Krusha Kannon that can fire a range of specialized rounds. Designed on the infamous Forge World of Tigrus millenia after the Orks had converted the planet into a huge Mekboy-run tinker shop, the Kill Krusha is an over-built and over-designed mess of a tank that absolutely ruins the days (and ends the lives) of everyone who opposes it. Having an entire Forge World's worth of shops and weapon designs on their hands, its no surprise that the Murda-Meks of Tigrus decided to "have good ideas" all over this
poor ZOGGIN BOOTIFUL tank.
Firstly, the Krusha Kannon is an all-too-powerful gun that sports a supremely complicated auto-loader design. Dubbed "a miracle of Orky design," this hair-brained device was probably equal parts a battlefield flexibility enhancer and an excuse to kick unscrupulous grot loaders out of the tank by greedy Ork gunners who just want to deafen themselves in peace. The end result was a collection of gubbinz and bits that was so complicated it forced a number of Grot Oilers to tend to the auto-loader in perpetuity (effectively putting as many Grots into the tank as it took out in the first place). The Krusha Kannon as a whole was trying to fill every armament role at once, while similar tanks like the Leman Russ, Sicarian and Macharius have different guns fitted for different roles. In battle there are sometimes jams from mechanical failure, or the attendant Grots getting caught in the gears. Other times the autoloader (or the Grots, or the gunner) loads the wrong shell. The worst possible failure can result in the shell being fitted in backwards, causing it to explode the breach and inflict horrendous damage to the Kill Krusha itself.
Secondly, the entire drive train of the tank is essentially fucked sideways. The original tanks must have either been designed by a single mad Mek or a committee of a dozen stubborn Meks for how poorly it was engineered. As a super-heavy main battle tank fit to take on multiple battlefield roles and win, the Kill Krusha roughly fills the same role for the Orks that the Macharius Heavy Tank holds for the Imperium. However between Orks demanding bigger and better tanks than their enemies and the Kill Krusha adhering to the "main battle tank" philosophy of both moving quickly, hitting hard, and taking a beating all at once, the tank has a very over-burdened transmission and suspension. While most Ork vehicles eschew suspension all-together, the Murda-Meks must have spent too long pouring over Imperial STC printouts, because the Kill Krusha is a shockingly fast and maneuverable tank, so long as it remains in optimal working order. Given the Orkish propensity for not worrying over details, these design choices were abominable; the tank's suspension and transmission had a tendency to explode violently when struck, throwing coil springs and gears everywhere whilst tearing itself apart. The tank rapidly gained a reputation for being "highly sprung." It worked great, until it didn't. None of this was helped by later efforts by other meks to make their own Kill Krushas, all of whom had some lunatic idea of how to "solve" the problem with the drives.
Regardless of the ever-present maintenance issues, the tank remains a flexible fighter and a tough nut to crack. The Krusha Kannon has numerous types of shells to chose from each turn, such as the standard high-explosive "Boom" shot, the armor-piercing "Tankhammas", the anti-infantry shrapnel "Scrap Kanisters," and the incendiary "Blast Burnas". Kill Krushas come in endless varieties, some sporting several Big Shootas in a crown of all-around coverage, some with banks of Rokkit Launchas to eliminate flanking vehicles, and a few over-ambitious Meks will further push the Krusha Kannon's complexity by adding ludicrous gyroscopic stabilizers. Some Krusha tanks are even commanded by Gretchin. Most every version of these Kill Krusha tanks are tended-to by a horde of numerous Grots who keep the rattling monster-tank going with constant hammer blows, bolt tightening, and judicious application of Oiler Squigs.