The UFO is a popular tourist attraction in Edirria, having the top to ride on and see the sights, as well as a cafe inside. The Shadow Star uses the UFO to hide from the kirbies. The UFO sometimes flies by the city, which results in several kirbys coming up to take every patch and sometimes the shadow star.
The UFO is an event in Kirby Air Ride. When the sky turns a blue color instead of light blue, the UFO will appear. There are two ways to get on, fly on (good luck) or use the garden in the sky via the volcano. The UFO has plenty of patches, and there will always be an All Patch in the center.
In Kirby Air Ride, the UFO is never referred to as a UFO. The game calls it a "Mysterious Flying Machine", it has no checkboxes centered on it, meaning it's name isn't mentioned there, and its theme song is shared with the rail fire, and the rail fire has the theme name.