A zoo worker in Senegal, Africa, put on a textbook demonstration showing visitors the exact reason why you don't attempt to be a lion in a cage.
Abdoulaye Wade, a guide at the Park Hann Zoo in Dakar, reportedly provoked the animal and then reached into the cage to impress a group of visitors. The lion latches onto Wade's arm and begins a tug-of-war with it. At one point, it appears the lion is close to tearing his arm completely off as people yell and throw stones at the lion in an attempt to get the lion to let go.
Finally, Wade punches the lion on the top of the head and it releases his arm. He walks over to the security barrier, arm covered in blood, but thankfully appears to still be fully intact.