The Middle-Son 1986 Class is a watercraft in the Metal Slug series. In the first Metal Slug, the player cannot control this huge Submarine. Instead he can use the mounted flak-turret of the Middleson.
The damage of the turret is about a pistolshot, but it is fast firing. Although the Middleson is armed with missile-launchers, the player can't use these.
Almost all information about the Middleson 1986 is kept secret by the regular office. It is only known that the Middleson 1986 is one of the oldest submarines of the regular army still in service constructed sometime in the 1980's.
It has an outdated hull of an U-boat, which is faster than a modern submarine when surfaced, but slower when submerged. The Middleson can carry ballistic missiles against land targets and a flak-turret against airborne enemies.