The Panzerkampfwagen VIII Maus (“Mouse”) was a German World War II super-heavy tank. It was the heaviest fully enclosed armored fighting vehicle ever built. Five were ordered, but only two hulls and one turret were completed before the testing grounds were captured by advancing Soviet military forces.

The Maus was a colossal machine, weighing in at 188 tons. It was armed with a 128mm main gun and a 75mm coaxial gun. The tank’s armor was also extremely thick, up to 240mm in some places.
Despite its impressive specifications, the Maus was never used in combat. It was simply too heavy and slow to be practical. The two prototypes were captured by the Soviets and are now on display in museums.
The Maus remains a fascinating example of German engineering during World War II. It is a reminder of the lengths to which the Nazis went in their quest for military dominance.

• https://en.wikipedia.org/wiki/Panzer_VIII_Maus
• https://nazigermanyguide.blog/2018/05/30/bizarre-nazi-weapons-the-maus-tank/