The bottom tier of the cake was a double-layer 8" round and the top tier was a double-layer 6" round, both were classic white with buttercream icing and a gumpaste Elmo sat on top.
Also, there were Elmo decorated sugar cookies, that turned out way cuter than I ever expected.
Here's a better pic with a professional photographer (makes me really want to get a fancy camera and learn how to take nice pictures of my cakes).