Luigi's Mansion
Gamecube Cameos

Neville's Book

The first Portrait Ghost you encounter is Neville. If you look closely at the book he's reading, it's titled "Mario Start" and has a side-view silhouette of Mario's head on the cover.

Submitted by angrysun

Melody's Music

The conservatory on the ground floor is filled with musical instruments. Activate them all by knocking on them and each instrument plays a part of the Super Mario Bros. Ground Theme.

Once the music is playing, Melody the Portrait Ghost will appear at the piano. She plays a song and you will have to guess what the composer had in mind while writing it. There are two songs she might play:

The Underwater theme, also from Super Mario Bros.
The Athletic theme from Super Mario Bros. 3.

Submitted by Fryguy64, YoungLink

Game Boy Horror

One of the tools E. Gadd gives you is the Game Boy Horror, based on the clear purple Game Boy Color.

When using it, it appears as a photo of the system. The only difference is that the word "Color" has been replaced with "Horror".

The Game Boy Horror plays an 8-bit rendition of the Luigi's Mansion theme when E. Gadd tries to communicates with you.

Submitted by Fryguy64

Meet the Pikmin

In the Options menu of the US and PAL versions of the game, you can find a promotional video for the upcoming game, Pikmin.

Submitted by Fryguy64, YoungLink

E. Gadd's Origin

Professor E. Gadd's Japanese name is Professor Oyamaa. He is named after the character's designer, Yoshiyuki Oyama.