Some years ago, Lara and I went on safari in Kenya. Whilst we were on a drive around the Aberdares, our driver spotted a young bull elephant coming towards us on the track. We were in an open-top 4x4 converted Land Rover with 6 seats. I was stood up balancing my camera / lens on the roll-bar when the elephant started to charge us. The driver didn't flinch and, taking that as a good sign, I stayed put and kept shooting. The elephant backed down when about 20 yards from us. When I turned around, the remaining 5 passengers were all crammed on the back seats, looking at me as if I was mental. To this day, I really don't know why I kept shooting - other than it looked like a scene from a film when viewed through the viewfinder and not "real". I'm just glad that the elephant did stop, though.
I'd post a couple of shots but they were taken on the "wrong" medium for this forum.