The staff is made of gold, with a jeweled ball at the end of it. The king used it to transform the Shaggy Man's head to that of a donkey, but the Magic Staff could not reverse the enchantment. The only way to break the enchantment is to bathe in the Truth Pond in the Land of Oz.
The king also used the staff to provide food for the Shaggy Man and his companions, giving each the type of food he or she liked best. (The Road to Oz)