Here is a picture of the question mark butterfly with the question mark circled. If you tilt your head to the right, it looks pretty close to what the punctuation mark looks like.
There are a few species of butterflies that are called "commas". They have a mark that looks something like a comma, and it is located in the same place.
Actually, they all look very similar from the side. You probably need to consult a good butterfly book to tell them apart.