The E-100 was ordered in June 1943 as a parallel development to the Maus. However, in 1944 Hitler put a stop to all development of Super Heavy Tanks. The chassis of the prototype was almost complete with only the turret missing when the war ended with the tank weighing in at an colossal 140 tons. It was to be powered by a 23litre Maybach HL230 engine generating 700bhp. The blueprints suggest a main gun of 149mm KwK 44 L/55 and a secondary co-axial 75mm KwK 44 L/38 as well as a 7.92mm MG34.