The M56 "Scorpion" self-propelled gun is an American unarmored, airmobile self-propelled tank destroyer, which was armed with a 90mm M54 gun with a simple blast shield, and an unprotected crew compartment.

It was powered by a Continental AOI-403-5 gasoline engine developing 200 brake horsepower (150 kW) at 3,000 rpm, allowing a maximum road speed of 28 miles per hour (45 km/h) and a maximum range of 140 miles (230 km).

Twenty-nine rounds of main gun ammunition were carried, and only the small 5 mm thick blast shield was armored.

Its function as an air-mobile, self-propelled, anti-tank vehicle was eventually replaced in Vietnam by the troubled but effective M551 Sheridan which had a fully armored turret.

As for foreign operators, Morocco was the only export customer which used M56 Scorpions in actual combat.