Mario Artist: Communication Kit
From the Super Mario Wiki
Mario Artist: Communication Kit is a game which served as an accessory in the Mario Artist series for the Nintendo 64DD. As with the other games, it was only released in Japan, on June 29, 2000. It allowed players to connect to a RandNetDD internet service and upload their creations in the games to the internet. It also allowed them to swap creations through the games. They could even ask Nintendo for a print out of them. The player can find pre-made content that they can download to the other three games via a secret option in the menu.