Ozzy Osbourne admits he's "done a lot of stupid" things.

The former Black Sabbath rocker - who infamously bit the head off a bat on stage and has battled alcoholism and drug abuse - is astonished he is still alive after all he has been through.

He said: "The fact that I've survived and I'm still recording. I've done a lot of stupid things but I've also done a lot of good things. Making it on my own as a solo act was an achievement. I don't take success for granted."

Ozzy - who is currently promoting his tenth solo album, `Scream' - has suffered his fair share of embarrassing moments on stage, particularly when he lost his voice and was unable to perform.

He admitted to the Metro newspaper: "I did a gig at Donington, in the early days of my solo career and my voice went. Nothing came out. Unlike a guitar player or a drummer with their instruments, I can't change my vocal chords."

Since he was sacked from Black Sabbath in 1979, Ozzy - who underwent emergency surgery in December 2003 following a quad biking accident - has continued to have a successful career and was rumoured to be having a film made of his life.

He explained: "Johnny Depp as going to play me at one point but then I had that bike accident and things were postponed. He's a very nice, cool man but I'd like an unknown guy from Birmingham to do it."

Ozzy will begin an 18- month world tour of Ozzfest later this month. He will be performing a one-off date at London's 02 arena on September 17th 2010 - where he is expected to take over the entire 02 complex with fairground rides and tattooists.