Wii Fit Trainer is a host character from the game of Wii Fit. The Trainer teaches players to use certain exercise routines in the game. She appears in Super Smash Bros for Wii U and 3ds as a playable character.
In the Wii Fit series, the player chooses between the Male Trainer or Female Trainer, who instructs through exercises and gives advice. The trainers can be swapped at any time, and may even occasionally fill in for each other.