Instructions
Select the "Media" option from the main menu by highlighting it and pressing the "A" button.
Select "Settings" and then "Appearance" from the submenu.
Select "Human" from the "Race" option of the submenu and return to the previous menu.
Select the "Armor" option from the "Appearance" menu. Use the directional pad to cycle through the options and select the smallest possible armor.
Return to the main menu. You have now created the smallest possible character in the game, though you may want to also change the color of your armor if your intent is to make your character harder to see.