The Antonov An-124 Ruslan is a large, four-engine, strategic airlift cargo aircraft designed in the Soviet Union. It is the world's largest military transport aircraft and is capable of carrying up to 150 tons of cargo. It is also the heaviest aircraft ever built and
From Wikipedia
The Antonov An-124 Ruslan is a large, strategic airlift, four-engined aircraft that was designed in the 1980s by the Antonov design bureau in the Ukrainian SSR of the Soviet Union (USSR). The An-124 is the world's second heaviest gross weight production cargo airplane and heaviest operating cargo aircraft, behind the destroyed one-off Antonov An-225 Mriya. The An-124 remains the largest military transport aircraft in service.