The release was the result of a Facebook vote.
Blue Yoshi has become available in Mario Tennis Open as the result of a recent Facebook poll determining favorite Yoshi color.
Available as a QR code, players can scan in the character by pressing up and start while on the Profile Select screen. Although treated as a totally separate character on the character select screen, Blue Yoshi carries the same focus on speed as the already-available green version.
You can see more details on these Yoshi characters in our Mario Tennis Open guide.
