An even larger tank, the 1000-ton Krupp P 1000 "Ratte", started construction but was cancelled before completion. It would have carried two 280 mm guns (mounted in the same type of gun turret used in Scharnhorst and Gneisenau warships) a single 128 mm gun, eight 20mm Flak 38 anti-aircraft guns and two 15 mm Mauser MG 151/15 guns.
The Ratte made the Maus look like its namesake. The Ratte was to be a nightmare machine and its scale still boggles the mind. It would have been 35 meters long, almost four times as wide as the Maus, and 11 meters high. Armor would have been similar or possibly slightly thicker than that seen on the Maus, but of course covering much more surface area. The tank would have been propelled along on a total of six 1.2 meter wide tread assemblies, three on each side of the tank. This means that the treads on one side would have been only slightly narrower than the entirety of a Maus. No less than eight Daimler E-boat engines would have provided the tank's requisite 16,000 horsepower.
The number of crew members is unknown but would have likely topped fifty men, with adequate machineguns studding the hull to engage infantry from all directions.
The Ratte would have been able to drive over trucks, houses, and even the mighty Maus tank with ease. Its guns would have leveled buildings, blasted craters ten meters across in the earth, or sunk an unfortunate naval cruiser loitering a little too close to shore. The term P.1000 was a reference to the estimated thousand ton weight of the Ratte, but odds are it would have been much closer to 2000 tons.
The tank would have been extremely slow - probably less than the paltry 20 kph the Maus could manage - and difficult to command effectively in combat. While its relative invulnerability would have made up for some of these shortcomings but something that big and that slow would have been destroyed one way or another.