The Super Plumber of Undertoad Mario is a mammoth, safe nation, remarkable for its burgeoning yoshi population. The hard-working population of 5.833 billion Undertoad Marioans have some civil rights, but not too many, enjoy the freedom to spend their money however they like, to a point, and take part in free and open elections, although not too often.

The medium-sized government juggles the competing demands of Law & Order, Defense, and Education. The average income tax rate is 23.3%.

The Undertoad Marioan economy, worth 244 trillion coins a year, is fairly diversified and led by the Book Publishing industry, with major contributions from Information Technology, Basket Weaving, and Tourism. State-owned companies are reasonably common. Average income is 41,891 coins, and evenly distributed, with the richest citizens earning only 3.2 times as much as the poorest.

Crime is almost non-existent, thanks to a well-funded police force and progressive social policies in education and welfare. Undertoad Mario's national animal is the yoshi.

Undertoad Mario is ranked 190,135^th in the world and 17^th in Xianzhou Alliance for Most Developed, scoring 52.93 on the Human Development Index.