We found out yesterday that Mario Sports Superstars for the Nintendo 3DS will launch on March 24th and will support amiibo cards. An eagle eyed Redditor has noticed that the art for certain cards has been reused from past Nintendo games.
The Bowser card is of Bowser breakdancing from Dance Dance Revolution: Mario Mix. This was a 2005 GameCube title.
And the Mario’s pitching pose is taken from art in Wii baseball game, Mario Sports Sluggers