Chrysalis or Cocoon?
Is a chrysalis like a cocoon? Is there a difference? Yes! Cocoons are the technical term for the silk casing that moths weave around themselves so that they can molt and transform and have wings.
For the sake of poetic rhythm, and because most of us are more familiar with the word cocoon, I decided to use that word for Millie's transformation in the book instead of chrysalis.
But it is actually a chrysalis that a butterfly needs in order to transform. And the amazing thing is that they actually molt into a chrysalis. The caterpillar's skin literally splits open and the chrysalis emerges! It's almost like they turn themselves inside out. As the chrysalis emerges and they shed their skin, the chrysalis is the special place where the butterfly takes shape. It is like a miracle of nature!