|Location||Brookly, NY (formerly), Mushroom Kingdom (currently)|
|Mushroom Kingdom, Toads, Mario, Luigi, Alfonso|
|Family and Relations|
| Mario (Brother) |
|First Appearance||Super Mario Throwback|
Gustavo is the younger brother of Mario, Luigi, and Alfonso. He is the youngest out of the four. Alfonso and Gustavo came to the Mushroom Kingdom to find their older brothers who had lived in the Mushroom Kingdom for a while. Gustavo looks similar to Luigi, but is thinner, shorter, has lighter hair, and wears blue instead of green. He is two years younger than Alfonso.
Despite his appearance, Gustavo is not much like Luigi personality wise. Gustavo is not as caring, he is a little more daring, he is stubborn, and he can hardly be convinced to do anything, unless it is for his brothers. When he was 8, Mario and Luigi went missing while doing a plumbing job. When Gustavo turned 18, he and Alfonso left to find Mario and Luigi.
Gustavo appears in Super Mario throwback as a default character.