Dream Machine

The Dream Machine is a machine used by Wart prior to the events of the non-Mario game, Yume Kōjō: Doki Doki Panic, and the Mario version, Super Mario Bros. 2.

Yume Kōjō: Doki Doki Panic
In Yume Kōjō: Doki Doki Panic, the Dream Machine is created by the Muu people to control the weather and sustain good dreams to all the inhabitants. Mamu (later renamed Wart) tampers with the Dream Machine to produce several monsters. The Muu people initially stop Mamu, but when the twins Piki and Poki accidentally rip out the last page of the book, Mamu attempts to rewrite the ending and kidnaps them. At the final battle, the Dream Machine creates turnips, which the twins' family has to throw four times in Mamu's open mouth in order to defeat him.

Super Mario Bros. 2
In Super Mario Bros. 2, the Dream Machine plays an identical role, although its background as the prize of the peace-loving people was not used from the story. It is still implied to create monsters that Wart then uses to increase the numbers of soldiers for the 8 bits and take control of Subcon. During the final battle, the Dream Machine shoots out vegetables, which are the only way to defeat Wart.

BS Super Mario USA
The Dream Machine made its return in the pseudo-sequel, BS Super Mario USA. It only makes an appearance in Wart's secret room in a jar from Subspace that is almost identical to that of the factory's final room. The Dream Machine is used for the same purpose it had in the first game.