Game Boy Horror

The Game Boy Horror is a device created by Professor E. Gadd that can be found and used by Luigi in Luigi's Mansion. It allows the elderly professor to contact with Luigi, which is the source of a few glitches. It has a map, the plumber's stats, the Portrait Ghost's information, and radar called the Boo Radar which can only track Boos. Luigi can browse in the Game Boy Horror's camera screen to allow the player to look at the mansion in the first person perspective by pressing the "X" button. The player could even scan/select certain objects and have the plumber say information about it, similar like the Tattle ability in the Paper Mario series. It could also be used on mirrors to teleport back to the Foyer.

Trivia

 * Using the Game Boy Horror in a dark room, a player could listen that the monsters are singing the Luigi's Mansion theme song.
 * If Luigi scans a mirror with the Game Boy Horror by pressing the "A" button after using the Game Boy Horror in first-person mode, he will be warped back to the Foyer of the 1st floor automatically, however, this does not work with the mirror in the Mirror Room.
 * The advanced/upgraded version of the Game Boy Horror, The Game Boy Horror SP, is a parody on Game Boy Advance SP. It made an appearance in Mario & Luigi: Superstar Saga.
 * Interestingly, if the player uses the Game Boy Horror's map function in the Training Room or the Gallery, they can see that there are four rooms connected to each other: the latter two, the lab, and the Ghost Portrificationizer room. There are also several doors visible in some of these rooms, but they are inaccessible; if the player tries to go through the one in the Training Room, it will not be possible. E. Gadd stands in front of the one in the Gallery. Also, on the map, there is a ladder visible in the lab; this possibly means E. Gadd's headquarters are underground.
 * In Luigi's Mansion: Dark Moon, Luigi uses a Nintendo DS called by E. Gadd the "Dual Scream" instead of the Game Boy Horror.