Dual Scream

E. Gadd giving the Dual Scream to Luigi at the beginning of the game.

“Ho ho! The terrified look in your eye just gave me a great idea. From now on, I'm going to call the DS — this is genius — the Dual Scream!”

—Professor Elvin Gadd, Luigi's Mansion: Dark Moon

The Dual Scream is a device designed by Professor Elvin Gadd in Luigi's Mansion: Dark Moon. Dual Scream is a pun on "dual screen" - the abbreviation "DS" in Nintendo DS, which is what the Dual Scream is modeled after. It functions similarly to the Game Boy Horror from Luigi's Mansion. It allows E. Gadd to communicate with Luigi, displays mission objectives and a map of the current mansion on the 3DS's bottom screen, and displays the pause menu on the 3DS's top screen when accessed. Its ringtone is a remix of the Luigi's Mansion theme.

Trivia

• While Nintendo DS speakers have a rectangular shape, the speakers of the Dual Scream are shaped like E. Gadd's head.
• The Game Boy Horror had its full name from the start of Luigi's Mansion, though the Dual Scream got its full name partway through Luigi's trek through the Gloomy Manor, when E. Gadd thinks up the idea after noticing the frightened look in Luigi's eye.
• The design of the Dual Scream is based off of the 1st original model of the Nintendo DS. E. Gadd asks Luigi if it "looks familiar" to him.
• In some missions of the Old Clockworks and Secret Mine, the signal is not good during the underground sections, and thus the screen is staticy and some letters of non-notable words are left blank similarly to how if you are play download play on your Nintendo DS with someone in real life and you go into another room, the game you are playing will have a bad connection.
• The Nintendo DS seen in Mario and Luigi: Partners in Time could be the Dual Scream considering Professor E. Gadd did not have a name for it until the events of Luigi's Mansion: Dark Moon.