This is a video of a lion attacking one of its trainers in Shiraz, Iran (south central Iran).
This amazing video clip was originally posted by Jalil268. I have added English subtitles for the benefit of non-Persian speakers.
The lion is hanging on to the man's arm and chewing! The man's friend/co-worker is holding on to the male lion's head so it won't be able drag the injured and bleeding man back in the middle of his cage to finish him off. The friend is screaming for help and begging for someone to find a stick, pistol or some other weapon to fight off or kill the lion! Watch and see the conclusion!