Panzer VIII Maus
Panzerkampfwagen VIII Maus ("Mouse") was a German World War II super-heavy tank completed in late 1944. It is the heaviest fully enclosed armoured 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.
Batillus-class supertanker
While being the largest ships ever built by gross tonnage until "Pioneering Spirit", the four "Batillus"-class ships were the second largest ever constructed when measuring deadweight tonnage or length overall, behind only the supertanker "Seawise Giant" (renamed four times, including "Knock Nevis"), which existed from 1979 to 2009.