In Paper Mario: The Thousand-Year Door, Goombella mentions having shoes. Since her sprite uses the same graphics for her feet as all the other Goombas in the game (with only a color change applied), this seems to imply that all Goombas are in fact wearing shoes. However, in Super Smash Bros. for Wii U, Goombella’s trophy shows a new design for her that adds soles to her feet, differentiating them from other Goombas and making them look more like shoes. While this design decision was most likely a coincidence, there is a chance that it could have been an attempt to clear up the above quote.
The texture for the Smash Bills from Super Smash Bros. for Wii U. The bill design features a person in a Mario hat, the signature of series creator Masahiro Sakurai, and a photo of Nintendo of Japan’s new development building, opened in 2014.