Hmm, I found one sort of in the same ballpark as your description...right here at Penguin: Cocoon
I also found one called Metamorphosis Butterfly, sold elsewhere. The product description is as follows:
Show the audience a small "caterpillar," seemingly asleep. The caterpillar, you explain, represents life. "In many ways we take the very things around us for granted, never realizing their beauty and potential until its too late. The caterpillar for example. A seemingly ordinary member of the animal kingdom. Yet through its magical abilities to weave silk thread, some of the most beautiful cloth in the world is created."
Bring out an intriguing piece of paper and continue, "And yet the caterpillar is only recognized for its beauty and majesty once it transforms."
Place the caterpillar in the center of the paper and fold it up. "Sad, but true, we in this world often ignore the beauty and potential of the seemingly plain and uninteresting. Only when presented with an image of glamour and color do we stand in awe!”
The magic words, and you open the paper. A butterfly flies out of the paper. The caterpillar is gone! Comes complete with everything you need. Very easy to do.
There is, of course, a much older effect where paper butterflies seemingly fly around atop a handheld oriental fan. It can easily be found here: Dancing Butterflies
If none of these suit your fancy, then may I suggest that you think of ways to create such an effect. Many top performers do just this...they imagine an effect they wish to perform, then they explore all the possible methods for acheiving their goal. Before you know it...they are entertaining us all with their clever thinking. You can do it, too!