Towards the later half of World War II, Nazi Germany began the planning of the Entwicklung series of tanks in an attempt to standardize the tank designs. E-100 was the heaviest tank to be standardized in the E-series as an analogue to the Maus. The E-100 was proposed by the Adler company and they began development of the vehicle, though its progress was limited due to other priorities in the war effort. By the end of the war, the Allied forces captured the German factories and testing grounds, where they discovered the partially completed E-100 hull. The hull was examined, evaluated, and ultimately scrapped in the post-war period.

Introduced in Update 1.53 "Firestorm", the monstrous E-100 is a very rare trophy vehicle that is only given out in events. The tank's turret is identical to that of its counterpart, the Maus, but it features a completely different hull that is lower and more compact in its dimensions. Additionally, the E-100 has improved mobility compared to the "Maus," though this super-heavy tank still falls short in mobility when compared to most other heavy tanks. A distinctive feature of the vehicle is the presence of armor skirts along both sides, providing good protection against shaped charges and anti-tank guided missiles. Nonetheless, with the support of allies, the E-100 remains a formidable tank for opponents.

It has the distinction of being the second Rank V gift vehicle in-game, with the first being the La-174. Unlike the La-174, the E-100 could only be obtained in the special tournament events, making its acquirement rare to the point of being one of the rarest tanks in the game. It was first available in the "Teutonic Giants" tournament held from a time span of January to March 2016. It was made available again in War Thunder's 5th Anniversary tournaments, then again in the War Thunder's 6th Birthday tournaments.