In Thailand, I was photographing a wreathed hornbill posing helpfully in a tree. After a few minutes, the bird got bored and decided I had been there long enough. It flew down and advanced, I retreated and fell backwards - but being a pro kept shooting. This was the (hardly cropped) result! I think it's the eyebrows that are the scariest. I escaped with the only damage being to my shoes and dignity. (My wife was capturing the scene on video, with great amusement).