In a saucepan over medium heat, combine the sugar, butter, evaporated milk, cream of tartar and salt. Mix well and bring to a boil. Cook to the soft ball stage at 234 degrees F (115 degrees C). A few drops will form a soft ball when dropped into cold water. Remove from heat and cool to room temperature. Add vanilla and beat until creamy and stiff. Roll into balls and shape like little potatoes. Roll each ball in cinnamon to coat, then press in pieces of chopped nuts to look like eyes. You can also dust with cocoa to simulate dirt.