Cut a triangle form leather and shape the sides just like in a picture, so they would look like a bat wings :)
Don't forget to cut a strip too.
About 1 cm wide and 2,5 cm long.
Gather the center with a sharp needle and strong thread.
Glue it with a hot glue gun to your hair bow.
Glue the leather strip on top to hide the thread in the center.
You can glue something on top or just leave it simple. I glued some fake fangs to make it look more vamp :D