The Tiger II or King Tiger (Königstiger in german) was the usual name of the German heavy tank Panzerkampfwagen VI Ausf. B, produced in small numbers (around 500 units) at the end of WWII.  It combined the strong armor of the Tiger I with the sloped shapes of the Panther. Its armor and long-range gun gave the King Tiger the advantage against virtually all opposing tanks. Despite a remarkable agility for such a heavy vehicle, the King Tiger was under-powered because it used the same engine as the much lighter Panther and Tiger I tanks. For this reason it consumed a lot of fuel just as it  began to run short due to allied bombing against German fuel plants. Overall, the King Tiger suffered from a disabling lack of mobility and proved to be more formidable in defensive than in offensive role. Also, due to the lack of testing, the King Tiger faced numerous technical issues.
Two different designs of the hull were initially proposed: one by Henschel and one by Porsche, both using the same turret provided by Krupp. Henschel eventually won the contract and all the King Tigers were produced by this firm. Two successive turrets were provided by Krupp, and the initial design which is sometimes wrongly named "Porsche turret" is in fact the initial Krupp design. This design shows rounded front and sloped sides, whereas the so called "Henschel turret" (in fact the new Krupp design) was simplified to easy the production.