The title of this article is conjectural; an official name for the article's subject has not been found, so it has been given a fitting title by editors. If an official name appears, it is requested that the article be moved to the correct name.
Miyamoto's Ghost is a ghost with the head of Shigeru Miyamoto who appears in the bloopers.
Miyamoto's Ghost is likely an homage to a segment in JonTron's Banjo-Kazooie: Nuts & Bolts review. Where he describes what if Super Mario 64 was teased as a platformer but released as a city simulator. Leading to the Miyamoto Ghost segment.
He is shown to be the boss of Nintendo as well as the leader of the Mario Rangers.