[[File:BabyMarioBabyLuigiDifferences.png|thumb|left|Baby Mario and Baby Luigi viewed side by side. The two share many similarities with each other but also have subtle differences other than the color.]]
Baby Mario has beady black eyes and his large trademark nose. Baby Mario has a layer of brown hair always covered by his trademark 'M' hat. Like most of the babies, his outfit eventually changed. In earlier appearances, Baby Mario wears nothing but a white diaper and his hat. He wears a yellow cape whenever he acquires a [[Super Star]]. Later on, he is given a new outfit in ''Mario Golf'', which he continues to wear in his spin-off appearances, sometimes with minor adjustments. In this design he wears a red shirt covered by blue overalls akin to his older self [[Mario]]. Originally, the shirt is short-sleeved during the Nintendo 64 era, but his shirt is currently long sleeved as his adult self as of ''[[Mario Kart: Double Dash]]''. He also wears a pair of light blue and white sneakers. His emblem was originally a lowercase M in ''Mario Tennis'', but ''Mario Superstar Baseball'' and subsequent games changed his emblem to a capital M as his adult self.
Baby Mario being the baby counterpart of Mario. He is about half the size of Mario, and has light blue shoes instead of brown. He still wears blue overalls and a red shirt. He doesn't have a mustache like regular Mario, because he is a baby. He has the same reddish brown hair as Mario, and even this early on, Baby Mario already has his famous red hat with his initial (M) on it.
