Two secret Bowser characters in Mario Tennis: Ultra Smash - Wii U

Two secret characters (Bowser Jr. and Dry Browser) will play against Mushroom Kingdom rivals in Mario Tennis: Ultra Smash.

Bowser Jr. from Mario Power Tennis on GameCube
Dry Bowser from Mario Tennis Open on 3DS

Mario tennis: Ultras Smash a Wii U exclusive game will be released on November 20th 2015.