UFO

From Miikipedia

A UFO is an unidentified flying object. These saucer-shaped vessels come in from outer space to take resources from the Miis on the Miillenial Plains. To do this, they either capture Mini Miis which they use as food, or they send out their very own troopers, the Scare Crows. Very little can be done to stop them, save the new Ray Guns.

Below, a picture of a fleet of UFOs.