I LOVE these Monster Cupcakes from The Novice Chef! You can use pretty much any cupcake you want as the base since the real focus is the decorations. I love that she used purple frosting for these, and obviously, the cotton candy hair! It reminds me of the troll dolls that were popular when I was younger with neon hair that stuck straight up. I love the one eye, as well!
There are some tricks to mastering the cotton candy hair (you can't just use any old cotton candy), so for instructions and details check out the whole post on The Novice Chef!