Wrap the top tier in black fondant and make a mortar board to place on top (either cover cardboard in fondant or make one out of gum past) or it. Then make the tassle out of fondant to stick on the top.
I use half of the wilton sports ball pan. I make the board out of 50% fondant/ 50% gumpaste at the beginning of the week so it is nice and hard. I cut a small part of the top of the ball of so the board can lay flat, cover it in fondant and attach the board with royal icing.