By the end of the war, the chassis of the prototype E-100 had been partially completed; it was shipped to the United Kingdom for trials, but was later scrapped.

The basic design was ordered by the Waffenamt as a parallel development to the Porsche Maus in June 1943.

It was the heaviest of the Entwicklung (E) series of vehicles, meant to standardize as many components as possible, in the 100 ton weight class; other designs were the E-10, E-25, E-50, E-75.

Two types of engines were proposed: one was a 700 hp Maybach HL230, with a transmission and turning mechanism borrowed from the Tiger II.

[5] The first prototype was never fully completed and was found by the 751st Field Artillery Battalion of the American forces in April 1945.