I made these cupcakes for Halloween a couple years ago; the same time I made the Jack Skellington Cupcakes and Owl Cupcakes. I think they turned out really great and they were a hit with the trick-or-treaters!
Each Cupcake is vanilla cake dyed a variety of colors (orange, yellow, purple and green) for a tye-dye effect when you bite into them. The pupils are brown M&Ms squished on top of green-dyed frosting for the iris while the red vein lines are just red-dyed frosting piped from a sandwich bag.
I positioned each eye pupil a little different for variety; so some were straight on and others were off to the side. CREEPY! but yummy!