Heavy tank
The Char 2C was one of the largest tanks ever produced. At the start of World War II, France and the Soviet Union were the only countries to have inventories of heavy tanks, such as the Char B1, T-35, and KV-1. The Matilda II was designed under the British infantry tank concept which is similar to the heavy tank having thick armor and weighing more than their other tanks. It’s usually separate because they have less firepower with their cruiser tanks (comparable to mediums) at the time having the same main armament but more machine guns. Later war examples were the German Tiger I and II, as well as the Soviet IS series. Note that "heavy" versus "medium" is more a question of tactical roles than weight; the Panther, for example, was a "medium" tank that outweighed most Allied "heavy" tanks.
Seawise Giant
Despite its great length, "Seawise Giant" was not the largest ship by gross tonnage, ranking fifth at 260,941 GT, behind the four 274,838 to 275,276 GT "Batillus"-class supertankers. It is the longest and largest by deadweight: 564,763 tonnes. "Batillus"-class ships and "Seawise Giant" were the largest self-propelled objects ever constructed.