You're mom is an ugly CPU Mii.
Wii Sports
She has a 45,000,000 skill level in Tennis, doubling with either Groot or Jahn. She has a 999,999 skill level in Baseball, and a -4 skill level in Boxing.
Wii Sports Resort
She has a Swordplay Duel skill level of 1443. She appears with Jahn and Egg in Basketball, her skill level in Basketball being 1222. She was nerfed in WSR, which makes her skill levels reasonable.
Trivia
- Her Japanese name is Anata no okāsan.
- She is based off of the "Yo Mama" meme.
Groot and You're Mom in a tennis match