Andy is a Mii from the Wii.
You may get them confused with andy (WarioWare)!
Andy (Wii) originally appeared as one of the 60 CPU Miis to be included with Wii Sports. Since then, he's appeared in Wii Sports, Wii Sports Resort, Wii Party, Wii Music, Wii Fit, Wii Fit Plus, and Wii Fit U. In most of these games, his internal ID is 020, however in Wii Music it is 30. His Mii data filename is cpu_mii_020.rcd in Wii Sports, mii_020.rsd in Wii Sports Resort, Wii Fit, and Wii Fit Plus, mii_020.ffsd in Wii Fit U, and is cpu_mii_db30.rsd in Wii Music. Wii Party combines all 100 Mii data files into one larger file named mii_rsd.bin in the same ordering as Wii Sports Resort.
As with every CPU Mii, he has Mingling turned off. His Mii name in his Mii data file is アンディー. In his Wii U/3DS-format Mii data file, he was originally created on a Wii (1).
His Mii data file does not contain any unused data.
In Wii Music, his Mii data file is slightly different. While it's mostly the same as it is in Wii Sports Resort, it now includes a filled out Mii ID and console ID. His Mii ID is 80-4e-a6-d8 and his console ID is c2-3d-21-af. His Mii ID tells us he was created on August 27, 2006 at 3:14:40 PM.
According to a September 2020 Nintendo leak about CPU Miis, Andy (Wii)'s nationality is North American.
In the files for Wii Sports, his dominant arm for Baseball (Batting) is right-handed, Baseball (Pitching) is right-handed, and Tennis is left-handed. His unused dominant arm for Boxing is right-handed. His Baseball Pitching style is normal. He's ranked 28 in Baseball, 24 in Boxing, and 16 in Tennis. His group IDs are 0, 1, and 0.
In the files for Wii Sports Resort, his Wii country ID is 1, like all CPU Miis. His dominant arm for Table Tennis is left-handed. He's ranked 11 in Swordplay, 96 in Basketball, 90 in Table Tennis, and 81 in Cycling. His unused Canoe and Debug ranks are both 20, matching his ID value of 020.
In Wii Party's Friend Connection game, the default score rankings establish a relationship between Andy (Wii) and Alex (Wii), with them being 4th in the worst friendships category at 34 points (Budding Buds).
A younger version of him also appears in the Boxing training gym (more details in this Wii Facts Plus post) found in Wii Sports and the Wii Fit games. On the left is the texture extracted from the game files.
Andy (Wii) appears in promo art for Wii Music playing the marimba and Wii Party playing Board Game Island. For some images, you may have to open them in a new tab to see the whole render.
Note that in his Wii Music render, some parts look slightly off. His mustache texture gets rendered over his nose model and texture, thus creating a strange illusion.
Note that in his Wii Party render, he's wearing her favorite color (orange) instead of the player color.
Names in other languages
Source: Wii Sports Resort