The popular indie game by Yacht Club Games, Shovel knight, just had it's amiibo outed, by GAME. The amiibo will feature Shovel Knight and will be able to be used in future YCG Games. However, we are not yet sure what the amiibo will unlock.
UPDATE: Yacht Club Games has confirmed that the Shovel Knight Amiibo is official and will bring 2-player mode into Shovel Knight.