This item was found elsewhere on the Cellar but not really catalogued, so I'll post this anyway and plug in more detail.
full story
It all happened at the Shaoshan Zoo in Taiwan. And they were following procedure, it appears; the croc was first hit with a tranquilizer dart, but when the vet went to handle it, the tranquilizer had not taken effect for some reason.
And bam, the arm's off. It's almost educational to see it, because with Steve Irwin and whatnot, we've only seen successful croc handling by those who know what to do.
So another zoo worker shot the croc with an actual gun, which caused it to drop the arm and stalk away. What's weird is that they didn't find a bullet hole in the croc later - it was hit, but not punctured, and left the arm out of a state of shock ("did that dude just shoot me? WTF").
Now the good news: the arm was reattached after a seven-hour surgery.