Guest C

Guest C is a Pre-loaded Mii available for use in titles that feature Mii support, which includes Wii Sports Games, Wii Party games, and other games with Mii support. He's also the default male Mii in the Mii Maker, only with darker skin.

Super Smash Bros. for WiiU & 3DS
The design of the Mii Brawler used in promotional material and in-game renders is based on an edited version of Guest C. His skin is brighter (as the default male Mii in Mii Maker has light skin) and his hair has a different design, along with the hair being black in color instead of brown.

Super Smash Bros Ultimate (Switch)
He (as a Mii Brawler) retains the same skin color and hair color as SSB4, but with a different hairstyle this time (which is the same as Yuya's and Ai's).

Trivia

 * You could have earned his badge for making 25 edits on "CPU Mii" articles, which is now disabled.
 * All you need to do to make his Mii is to change the default male Mii's skin color to white with yellow undertones which means he is the easiest Mii