Not a butterfly but I've had a pigeon fly through my bike frame as I was riding along. Here in London there's loads of them, and as strong fliers with street smarts they leave it until the last possible second before getting out of the way. This one I almost ran over as it was walking along the road, I thought he was walking away but he suddenly veered back around and took flight like the Millenium Falcon, straight through my frame. I did catch it with my legs as it did it, but he corrected and styled it out and flew off. Proper Top Gun.