Ultra Box

The Four Horsemen, also known as Ultra Box, were a squad of four elite assassins that specialized in close-quarters-combat and were sent to assassinate Solid Snake, the titular protagonist of Metal Gear 2: Solid Snake.

Backstory
The Four Horsemen were composed of units originally aligned to the SAS, GSG-9, and UDT. They took orders directly from Zanzibar Land's president, Big Boss and his second-in-command, Gray Fox.

Metal Gear 2: Solid Snake
In Zanzibar Land's tower, the Four Horsemen found and fought Solid Snake in the central elevator. Despite their skills and numbers, however, Snake beat and killed all of them single-handedly.