At the end of each year, the preschool class I teach does a butterfly unit. We learn about the process of metamorphosis by reading books, doing art projects, puzzles, and even watching real live caterpillars make chrysalises and hatch into butterflies. Of course, we read Eric Carle's "The Very Hungry Caterpillar".
For a last day celebration, I decided to make a Very Hungry Caterpillar out of cupcakes. Each kid got to frost and eat one segment of the caterpillar--it made a colorful and fun special snack!