I had the pleasure of working on a Cuponk cup design a couple of years ago for Hasbro. The design was never released, but I had a blast working on it. I've included in progress sketches and work from the project. It was art directed by Drew Dougherty. You can learn more about the product here: http://www.hasbro.com/games/en_US/cuponk/
Final artwork cropped
Final artwork with guides and ID label
detail
detail
detail
detail
tightened sketch of final design
getting closer to final design
early exploration sketch
early exploration sketch
Giger-esque exploration sketch