Game Boy Horror is a type of Game Boy resembling the Game Boy Color in Luigi's Mansion that Luigi obtains from Professor E. Gadd. The professor initially had the item, but due to his retirement in ghost hunting, upon meeting Luigi in the mansion, he gives him the Game Boy Horror along with the Poltergust 3000.
The Game Boy Horror offers much assistance to Luigi on his adventure. It has five primary functions throughout the game. Below is a list of the Game Boy Horror's primary functions:
- It can find Boos via the Boo Radar.*
- It can read Ghost's hearts.
- It can point at stuff and Luigi says his opinion.
- It can function as a map of the mansion.
- It can list items Luigi has obtained such as coins, jewels, and Mario's items. This function also lists information on caught Portrait Ghosts.