Nazi Germany was very into tank warfare. Naturally, when you take over Europe you mostly do it on land, and having a tank can be an incredible tactical and psychological advantage. Hitler wanted to press that advantage to the hilt, so he tasked his engineers with creating ever-larger and more imposing vehicles.
The Landkreuzer P. 1000 Ratte was the apotheosis of this philosophy – a 1,000-ton armored dreadnaught that boasted a 128mm anti-tank gun, eight anti-aircraft guns and even an internal garage to store motorcycles for scouting. The Ratte was so heavy that it would have destroyed any roads it drove on, making them unusable. The project was scrapped in early 1943 and none were ever completed.