As the title suggests, explain how you defeated/reacted to the Legendary Bloatfly when you first saw it.

I for one, recorded my first two attempts. Once on normal, once on very hard.

Attempt 1 (Normal, Successful) : http://www.youtube.com/watch?v=Y2DnBTXidP4

Attempt 2 (Very Hard, Utter Failure) : http://www.youtube.com/watch?v=xowuBnH8uGY

(Yes those are my first attempts, however I had the advantage of knowing what was in the cave before I entered it though, so I was much better equipped then I would usually have been.)

I hid most of the time and kept peeking my head out to shoot it with the AMR with Incendiary Rounds on Very Hard. Died a bunch of times due to being one-hit every time.

Hunting Shotgun+ with And Stay Back! and Shotgun Surgeon. Bloatfly was on the ground for the entire fight.