Underworld (アンダーワールド Andāwārudo?) is the tenth and final world in Parasol Stars. It is a hellish realm filled with monsters, and is where Chaostikhan makes his lair.
Several elements of the world are themed after Chack'n Pop, including the heavy presence of Monstas and Maitas, the layout of the first round of the world being based off the first level of Chack'n Pop, Chaostikhan's first form being a black-robed Maita, and the giant Chack'n that the player frees after defeating the boss.