The Panzer VIII Maus was a super-heavy tank that was developed by Germany during World War II, albeit not put into mass production, for a variety of reasons, notably its excessive size and production costs.
The Maus had a Daimler MB509 V12 gasoline engine, which was later switched with the Daimler Benz MB517 diesel engine that was capable of propelling the Maus at speeds of up to 13 km/h. It also had a crew of six and was armed with a PaK 44 and 75 mm KwK 44, along with an MG 34 co-axial machine gun.
The maximum range of the Maus was about 190kilometers and the about sixty-eight 128 mm ammunition could be carried on board, along with two hundred 75 mm rounds. The type of radio used aboard the Maus was a FuG 5 and the armor protection across the tank varied from 200 mm to 160 mm.
The total weight of the Maus was about 191,000 kilograms and the length was ten meters. The height was 3.6 meters and the width was also 3.6 meters. The Maus also had a two speed forward, two speed reverse transmission system.
The first prototype of the Maus was a turretless version, called the V1. It had faced several problems including engines that were simply too weak to pull the giant hulk and that the tank was so heavy, it would shatter most bridges. If the Maus was to see combat in the Western or Eastern Front, it would face many rivers, and this would become a tremendous problem. To solve this problem, designers made the Maus capable of actually driving through rivers with a depth of up to 13.7 meters. To do this however, two tanks were required to ford in pairs, because one would be needed to power the other's electric transmission.
The V2 prototype was delivered in 1944 and was the first to feature the actual turret, unlike the V1 which had to make use of a concrete turret for testing. Four other Maus tanks were ordered, and a flak version, which would feature twin FlaK 18 cannons, was also looked into during the war.
Development of the Maus began in 1941 and the V1 prototype, which had no turret was delivered in 1943. The Maus was the largest tank of the war and the largest tank in history (unless you count the proposed Landkreuzer P.1000 Ratte). It is debated to this day if the Maus ever saw combat, although Russian accounts say that it saw combat at the factory where one was captured and also during the Russian advance into Germany. Other Maus prototypes (mainly just unassembled hulls) were captured around Germany. The only prototype left is at the Kubinka Tank Museum, outside of Moscow. Only nine, in various stages, Maus tanks were ever made. Recently, in 2011, WarGaming announced they would be working with the Kubinka Tank Museum to try and restore the Maus prototype to working condition, though nothing else has been revealed about this project and the Museum seems less than enthusiastic. This announcement was supposedly a joke, however.