8in square and 6in round- buttercream and fondant/gum paste decorations- -- Mike is styro covered in fondant-- the original Mike was RKT but he was not big enough- so thankfully at 2am I found some styro at the bottom of one of my many storage boxes!! Whew- that was a stroke of luck! Cupcakes were completed 10 minutes before pick- up. Wish I had had a little more time! Thank you to all those who have posted Monster Inc. cake photos- they were certainly my inspiration - ooh there is a surprise inside-- colored cake circles (blue green purple) hope that works out when they cut it- ha!!! Thanks for looking - :)