Shroob Mother Ship

The Shroob Mother Ship is a large spacecraft primarily used by Princess Shroob for combat and transportation in Mario & Luigi: Partners in Time. The ship resembles a large, pink Shroob UFO; subsequent to their invasion of Mario's planet, the Shroob's mothership usually appears to hamper the bros. efforts to halt the Shroob invasion. The Shroob Mother Ship is the only full-length area in the game that cannot be accessed once the four heroes leave.

History
After Mario and Luigi defeat Bowser and Baby Bowser in Thwomp Caverns and seemingly rescued Princess Peach, the Shroob Mother Ship sucks Mario, Luigi, the babies (Baby Mario and Baby Luigi) and "Peach" into the ship. While inside the Shroob flagship, the Mario Bros. discover that the "Peach" they had rescued from the Bowsers is actually Princess Shroob in disguise, and the Princess promptly tries to destroy Mario and company. Before she succeeds, however, Kylie Koopa saves the Bros.. The heroes then travel to the mothership's second floor, and while trying to use a key on that floor, the Bros. get dropped into the now-wrecked Toad Town.

The Ship itself is largely linear and pseudo-2D, with long, straight sections which wrap around the perimeter of the ship and overlook a vast pool of slime in which several Shroobs are swimming. Guardian Shroobs patrol the area, and can be battled for experience points.

Later, while in the Shroob's Castle, the Mario Bros. use the mothership to destroy various smaller Shroob UFOs. Shortly after piloting the mothership, the Bros. finally find the real Peach; however, Princess Shroob then takes the opportunity to use the mothership to open fire on her own castle in an attempt to finish the Bros., forcing them to engage the mothership in battle by using the castle's own head, which has an interior identical in layout to the room inside the Mother Ship that the Mario Bros. had used earlier. After its defeat, the Shroob Mother Ship crashes into Shroob Castle, taking out a barrier which had imprisoned Peach before the ship's destruction.