Lumbiaco (ロムビアコ, Romubiako, 31): Lumbiaco is a monster from the Sound World (サウンドワールド, Saundo Wārudo), which was destroyed by Kireizky, who comes to the Human World with the intent to feed on its noises. By doing so, it grows in size and takes a nap before it feeds again, with the cycle repeating until it's too big for the world to hold. The only means to shrink it is with beautiful sound, which Lumbaico hates and goes on a rampage upon hearing. In the end, the monster is stopped by the specially assembled G3 Princess group who shrink him and destroy him with their attack.