Dancing Mii
Select your Mii at the main menu and it will do different things. If you select its right arm, it will give you a thumbs up. If you select its left arm, it will wave. If you select its head, it will shake it. If you select its torso, it will jump. If you select its right leg, it will lift it up along with its hands. If you select its left leg, it will act as if it is about to fall.