Ozzy Osbourne died of heart attack, death certificate reveals

Heavy metal legend Ozzy Osbourne died of a heart attack, coronary artery disease and Parkinson's disease.

That's according to the his death certificate which was obtained by The New York Times on Tuesday.

The former Black Sabbath frontman died on July 22 at the age of 76 and was best known for his unique heavy metal voice, outrageous acts and his absurd MTV series "The Osbournes."

Osbourne's funeral was held in the city of Birmingham, England on July 30.