Mario Artist: Communication Kit
From the Super Mario Wiki
Mario Artist: Communication Kit was a game which served as an accessory in the Mario Artist series for the ill-fated 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 3 games via a secret option in the menu.