Shroob saucer
Shroob UFOs are the Shroobs' alien spaceships that they use for travel from place to place. These spaceships are small; however, they can shoot powerful energy bolts that can turn people into Shroob Mushrooms, as well as dealing devestating damage to buildings and such. They also shot Yoob with a special energy beam at one point, that caused him to grow huge, as well as making a Yoob factory and a horde of RC Shroobers appear inside him. Shroob UFOS are powered by Swiggler, the bio-engineered creature that the alien Shroobs created. In the final part of the battle against the Elder Shrooboid, there is a special UFO with a timer, and if the timer hits 0, the UFO will instanly defeat the four Mario Bros.
The UFOs only appear in Mario & Luigi: Partners in Time.