Game Boy Camera
“Smile! You're on Game Boy Camera!”
The Game Boy Camera, known as Pocket Camera (ポケットカメラ, Pokettokamera) in Japan, is an accessory for the Game Boy (and compatible with the Game Boy Color and Game Boy Advance) released in early 1998 which allows the user to take up to 30 grainy monochrome pictures (although that amount can be increased through third-party devices) and view them and edit them on the Game Boy screen and print them out using the Game Boy Printer. It was discontinued in 2002. Both the camera and the printer contain many references to the Mario franchise.
Quoted from the box.
Turn any Game Boy system into a digital camera!
Game Boy™ Printer
Look for the Game Boy Printer
In other media
A comic called "Rummelplatzquatsch" was made to promote the Camera in Germany, and also featured the Camera heavily.
The comic centers around a Game Boy Camera used by a self-proclaimed fortune-teller to foresee the future. Mario falls for the trick when the Game Boy Camera depicts a toilet brush to him and few seconds later such a brush is dashed into his face indeed. Immediately he buys the Camera, being excited about foreseeing his own future. However, the device only brings misfortune to him. After depicting a cake, one is thrown into his face; after depicting a train, he is run down by one; and so on.
Trying to get rid of the Camera, Mario returns to the fortune-teller who turns out to be Luigi, explaining that it was just a normal Game Boy Camera he sold to his brother, and that it cannot foresee the future. He attempts to prove his point by turning the device on. After it shows Poochy, suddenly a herd of dogs enters the tent. Now Luigi is terrified as well and the brothers run away, dropping the Camera. At the end of the comic, the reader sees Satan's hand grabbing the Game Boy Camera, and it is explained that this is the only copy that has fallen into his hands.