Inspired by this, but something completely different ;-)
Took about 20 minutes:
1. copied the butterfly shape from my book about insects
2. ironed some fusible interfacing on a scrap of fabric (mine is an old cotton print)
3. drew butterfly shape on interfacing + cut out
4. took a special needle for pins, sewed it to a little piece of wool felt and then sewed the felt to the butterfly shape.
Then I could already pin it on! :-)