Regular Missingno.

Missingno. is a rare Pokemon that has a slim encounter rate on any route, and in any region. While not an official Pokemon, Missingno.'s appearance on VDex matches that of the most common one in Pokemon Red Version and Pokemon Blue Version. Missingno. does have a shiny form like every other Pokemon, and can be found shiny in the wild.

VDex Wiki Shiny Missingno

Shiny Missingno.