Okay, so this one is pretty popular, and it turns out that it's absolutely true without any question of doubt. There were plenty of witnesses who saw the dazed Rock star making a rather idiotic or desperate move to wow his fans whilst he was on stage.
During a rather raucous performance, one of his fans threw an unconscious bat on stage (where you would find an unconscious bat is another thing entirely). Whilst Ozzy was channeling his Satanic stage presence, he mistook the live rodent for a stage prop - and the rest is history. We'll spare you the gory details, but he did go to get a rabies shot after his performance. The video is even available on YouTube if you're brave enough to watch.