It is often referred to as the Caspian Sea Monster. To my eye, it looks more like a spacecraft from a sci-fi movie than a creature of cryptozoology. It is, in fact, a huge vessel, part plane, and part ship, that has lay abandoned on the shore of the Caspian Sea for three decades.
It is more properly known as a Lun-class Ekranoplan, the only one of its kind ever put into service, between 1987 and sometime in the 1990s. An Ekranoplan, also known as a Ground Effect Vehicle, is classified by IMO as a ship, but derives its unique high-speed capabilities by skimming the surface of the water at a height of between one and five meters (three to 16 feet). The aerodynamic ground effect allows low drag and relatively high speeds.