In the arcade versions of the game, there's a hidden message in the files:

While the first three lines were overwritten with other data in the American build, the rest survived unchanged.

According to series creator Shigeru Miyamoto, Mario's appearance was the result of graphical limitations in the original Donkey Kong: his overalls allowed his arms to be visible against his body (as there was no room for outlines), his hat substituted for hair and eyebrows (and did not need to be animated when he jumped), and the large nose and mustache made up for the lack of space to depict a mouth.

Miyamoto additionally stated that the design was influenced by the decision to make Mario Italian-American, identifying his large nose in particular as a distinctly western feature.