Luigi's Mansion/Items/Game Boy Horror
The Game Boy Horror is a tool that Luigi uses to see a map of the mansion that shows him where keys are. This creation is made by Professor E. Gadd. The Game Boy Horror can also track how much money you have and let you see what boss ghosts you have defeated. But the main feature of this device is that you use it to track Boos, a blue indicator means no Boo is in the room, a green indicator means a ghost has been located in the room, and a red indicator means there is a ghost in the closest object to you.