Transmutational Brainwave Analyzer
From the Super Mario Wiki
The Transmutational Brainwave Analyzer is an invention created by Kooky von Koopa. It appears in the The Adventures of Super Mario Bros. 3 and the episode, "Mush-Rumors". Due to an "alien" invasion in Mushroom Kingdom (which is in fact due to Real World humans accidentally driving into a Warp Zone that led them there), King Koopa wants to hear the aliens' plans to conquer the Mushroom Kingdom. To King Koopa's surprise, they do not transform from their "disguises" into actual alien monsters, and Kootie Pie screams that they are still trying to trick them. Kooky von Koopa then proclaims that the Koopas will trick them.
Kooky von Koopa then explains his device to King Koopa: the Analyzer will send waves of some sort to read their minds when the humans are attached to the machine via helmet. The Koopalings will then know all of the humans' secret plans to conquer the Mushroom Kingdom, and then conquer the Mushroom Kingdom using these plans.
After the family gets their mind read by Kooky's contraption, Mario and Luigi break in and turns off the machine, thus freeing the family. Then, a hesitant Kooky von Koopa says that the Analyzer did reveal them as Real World people who were headed to an amusement park called Wild Waldo's One-of-a-Kind Amusement Park. An enraged King Koopa demands to know who started the "alien" fiasco, causing the Koopalings to point at each other.