Staff Ghosts are members of the Nintendo team that set staff times for one to try and beat. However, they only appear in Time Trials. Staff Ghosts were introduced in Mario Kart: Double Dash!!. Like regular ghosts, they appear as semi-transparent characters and behave as players who used them. These drivers cannot be touched and pass through karts and obstacles. One's personal best has to be better than the staff time of a ghost in order to unlock Expert Staff Ghosts, which only appeared in Mario Kart Wii and Mario Kart 7, which in turn unlock characters, vehicles, or stamps.