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From Unmariowiki

A bowl of cheese.

Cheese, perhaps better known as Nitroglycerin, is a mysterious substance first seen in Super Mario: Just Click You're Browser's Back Button. In this game, cheese was what the final boss used to power the Titanic, his kangaroo-shaped jumbo jet.

Cheese was later seen in Episode 38 of SMK, where Para-Hoopa stumbled upon a long-lost cheese mine in Cheese Land in his race against GoomBob. While Para-Hoopa initially did not wish to interact with the cheese mine, he soon almost found himself as its guardian when Bob The Builder held him at gunpoint and made him swear to protect it. Just then, Goombob ran over Bob and killed him, so Para-Hoopa could leave. eventually some idiot took over.

Although popular belief states that cheese is indeed existent in the Real World; this is actually just an urban myth, as what is often called "cheese" on the Real World is, in actuality, a variety of calendar (more specifically, a rare, polka-dotted type). Cheese is actually native to Planet Popstar, which makes an appearance by cheese rather rare in Mario games. Cheese did, however, earn a reference in the Yoshi-themed film Attack of the Strawberry-Flavored Brain Munchers, where George W. Bush's warning to the country of America was "I rly lyk cheese dont u?".