Answer:
Yes he did, at one of his concerts in Des Moines, Iowa. Accidentally. At certain shows Ozzy would throw raw meat at the crowd before the band started playing. Every now and again the fans would throw stuff back. They would throw raw meat and rubber animals. One fan threw a live bat on stage. The bat, stunned by the stage lights, did not move a muscle. Ozzy, thinking it was a rubber bat, bit the head off. After this he was promptly rushed to the hospital and was given multiple shots to prevent rabies. He also bit the head of a dove off during a CBS meeting, but this wasn't on accident. He bit the head off of the dove to induce a sort of shock factor, because he was getting angry with the managers and producers. He was also very intoxicated and/or under the influence at the time, as he explains in his recent autobiography; 'I AM OZZY'. Many critics believe that this helped to spark popularity when he began his solo career.