Someone recently posted a tutorial on that very thing, but I can't find it right now. She showed the two-tone and everything. I'll keep searching - but it's on here somewhere!
I cut triangles and stuck them in around elmo, but if I did it again I think I would cut a hole to stick him into and have it peeling back more...look at mine and see what i mean..........
http://cakecentral.com/modules.php?name=gallery&file=displayimage&pid=1558107
I only just stumbled across your question, would have been happy to help if you had asked me.
The design comes from the Planet Cake book. What i did was cut out 2 circles of the green colour and placed them in the middle of the cake on top of each other. Brush the top circle with syrup. I then covered the cake in yellow fondant. You can see the outline of the circle underneath, i then cut lines through the circle like a pizza, don't cut to deep you only want to cut through the yellow fondant and one layer of green. Then i peeled them back to create the explosion.
Hope that makes sense.
Nah on second thought I think my Elmo looks great, would not change a thing 
Quote by @%username% on %date%
%body%