When I've start playing this (about 4 years ago) Butterfly was unbreedable and only obtainable as reward after reach level 10 on one of the same developer's games (don't recall exactly wich one now).  And don't know exactly what was changed too, but I think you need a upgraded Breeding Temple to get one at this time. the 5-6 I've got, despite the 1st-rewarded one, came to me that way.

So, the answer to your question is: Spicy. ;)

You can easily breed Butterfly. I did it myself with level 4 to 9 dragons and a level 1 breeding mountain.