Jason Momoa feared "s******* my pants" hosting Black Sabbath's final concert.

The Aquaman star was invited by Sharon Osbourne to emcee her husband Ozzy Osbourne's last hurrah onstage with his bandmates at the legendary metal extravaganza, Back To The Beginning, at Birmingham's Villa Park on July 5.

However, the 45-year-old Hollywood star admits he gets "terrified" doing anything onstage, and just the thought of standing in front of people in a packed venue makes him feel physically ill.

He told Kerrang! magazine of getting the call to host the epic send-off: "I'm like, 'What the f*** are you talking about, man?!'

"I've never hosted anything before but I've gotta go out in front of all these f****** people and host! I'll be s******* my pants, but at the same time it's the goddamn greatest metal show in history."

The Chief Of War star is also "f****** terrified" anytime he steps onstage with his band ÖOF TATATÁ, who currently perform covers.

And, although he's busy with his acting, Momoa wants to hone his bass skills and is keen to get into their under-construction studio to record more original material with his bandmates.

He said: "We play everything from Zeppelin to Sabbath to Metallica to Bad Brains, and we switch it up, but it's all stuff we love that we haven't heard in a while, and people f****** loved it. Now we've started making our studio and we've got one original song, but I've been doing movies so much that I haven't had chance. We'll make our own original songs and do it up, but for now it's just buddies having a great time together."

Expanding on his huge fear of performing in front of a live audience, he said: "I'm f****** terrified. I'm not scared to act because I don't have to look at the camera and there are no crowds. I've never done theatre and I don't ever want to. I didn't get into acting to do theatre, I come from photography, cinema, shooting skate videos and s*** like that. I love film because you've got the writing, the music and the pictures. Theatre isn't really me. Standing up there with everyone staring at you all the f****** time is brutal. I get sick, I don't feel well, it's been this huge, whole different thing."

Momoa - who has Lola, 17, and Nakoa-Wolf, 16, with ex-wife Lisa Bonet - also loves that his kids have been getting involved in his band.

He continued: "I never wanted to be a rock star onstage, but it's really fun doing this thing and it helps my friends, and now my kids come and sing four songs, my son comes on and plays, and [we played] the f****** Whisky! I never knew I was going to do that, it was never in my brain to do that. I played in London! It's surreal. I don't care if it's 200 people or 5,000, it's still scary as s***. I love the bass and I really want to have more time to get better. I love music and I love learning."