In real life, Shigeru Miyamoto is a famous video game designer responsible for creating many iconic game series, such as Mario, the Legend of Zelda, Star Fox, Pikmin, and many others. In the world of the Insane Quest, however, Miyamoto is also a godlike entity whose power seems to be almost equal to that of Nintendoki. Shigeru Miyamoto often shows up at unexpected times to help Smoosh with whatever predicament they've currently gotten themselves into. Miyamoto is armed with a Wii Remote that he can transform into a seemingly infinite number of objects, including a sword, a goat, and a reality-warping device.
Miyamoto first appeared in Chapter I, where he offered his services to help save Luna Ravenheart from the clutches of Chibi. During the ensuing battle, Chibi appeared to destroy Miyamoto, and he was presumed dead.
Later, in Chapter III, Smoosh reunited with Miyamoto while visiting Planet Suda. Miyamoto revealed to the heroes that Doosh had taken residence on the planet and was slowly replacing the members of the United Assassins Association with even more powerful assassins in order to sabotage Travis Touchdown's ascending of the ranks for reasons unknown. Because it was important for Travis to become the number 1 Assassin in the UAA, Miyamoto had been training Travis so he would be strong enough to take on these new opponents. His plan was cut short, however, when Doosh began a full-scale assault on Planet Suda.
Miyamoto's latest appearance was in Chapter IV, where he, with the help of Mortal, was able to free Smoosh from Hades's dungeon.