Perhaps the final draft for a German super-heavy , all purpose tank, was the p-1500 Monster. Starting at 1500 tonnes, this thing would have been even larger than the p-1000 Ratte.

Ratte


In fact , it was planned to be almost 30% larger than the p. 1000 Ratte. As such, the radical resigned of the Monster called for four sets of tracks, about 1/2 the size of the Ratte. These would be put into all four corners of the massive tank, and the thing would move around, slowly , but steadily. Accordingly, this would have created a gyroscopic effect, allowing the massive Schwerer Gustav 800mm Siege Cannon, initially too large to fire even from a rail, to fire without toppling the Monster.

P1500 Monster Concept


The armour would have maxed out at 260mm all around, but the Monster was really created for indirect bombardment, not direct conflict. Much like the Ratte  , the thing was equipped with machineguns and aa guns, but they were only implemented because it was quite obvious the allied airforces would make a "huge target" of the p1500.

Monster Stationary Inaccurate Sketch


Following the first completion of a Maus prototype, the concept was dropped. But the Design idea was stolen from the Germans and used to create the super heavy American Bagger 288 (civilian vehicle).

Bagger 288

Much like something else was copied :P