Ozzy Osbourne shouldn’t be here. His legendary excesses include snorting a line of ants. During an interview for the documentary “The Decline of Western Civilization, Part II: The Metal Years,” he explains, while making breakfast, that everybody in Black Sabbath ended up junkies, alcoholics and in rehab.

“Drugs are OK at the time,” he explained. “but then it isn’t a very good idea anymore.”

While saying this in the film, Osbourne confidently tries to pour orange juice into a cup and spills most of it on the table instead.

When Osbourne plays the Voodoo Music and Arts Experience on Saturday, Halloween, it won’t be with Rock and Roll Hall of Famers Black Sabbath. Sabbath guitarist Tony Iommi was diagnosed with cancer late last year, and his health has curtailed his musical activities. The band plans one final tour, which Osbourne insists really will be it.

“He said he’s doing fine,” Ozzy said by phone. “He sounds fine. I’m keeping my fingers crossed. I’m sure he’ll be all right.”

Instead, Osbourne will perform at Voodoo with members of his own band, Sabbath bassist Geezer Butler, former Guns N’ Roses guitarist Slash, and Tom Morello, former guitarist with Rage Against the Machine.

“I’ve met him a few times, but I’ve never played with him,” Osbourne said of Morello. “I’ve never heard anything but good things said about him.”

On the other hand, he has known Slash for years. They played guest spots in each other’s concerts, and Ozzy appeared on Slash’s self-titled album in 2010.

Osborne has been a fan of Slash since the days of Guns N’ Roses, and let him know that he thought the band blew it when it imploded.

“That was the next Rolling Stones,” Osbourne told him. “In my career, there have been The Beatles, The Rolling Stones, Led Zeppelin, and a couple of others. That many have reached the pinnacle, and you blew it.”

These days, Osbourne is focused on live performances on his own and with Black Sabbath. In interviews, he talks about a possible new album, but he doesn’t sound committed. He and his wife and manager, Sharon Osbourne, have talked about a blues record, but he doesn’t say that with any certainty.

He has a few songs written, but one thing he learned with 2010’s “Scream” is the importance of a block of time, a stable environment, and a band. He didn’t have any of those when he began work on the album, so it was very much the product of producer Kevin Churko.

It reached No. 4 on Billboard’s album chart, but it seemed like the too-obvious culmination of a marketing plan, following as it did on the heels of the publication of his autobiography, “I Am Ozzy,” and the early release of tracks from it straight to the Rock Band video game. Ozzy came off more like the Prince of Synergy than the Prince of Darkness.

Osbourne attributes the distracted effort to “The Osbournes,” the MTV reality show that featured his family from 2002 to 2005.

“On my last two albums, I wasn’t that into doing them,” he said. “When that TV thing happened, it took me a while to find out who I was again.”

He remembers the taping being OK at first, but he quickly tired of the intrusion of cameras, lights, and boom microphone operators in the house. Still, Osbourne takes some irascible pride in the fact that the show was real.

“I can honestly say that was 100 percent real TV,” he said. “Saying that, I never watched one episode. I hate to see me on TV.”

Whether he likes it or not, “The Osbournes” changed America’s relationship to Ozzy.

In Black Sabbath, he was genuinely unsettling. By the 1980s, he had become an icon for bad behavior, as much sideshow freak as rock star. The show presented him as a dad — one slightly addled by prescription pills — and it became easier to feel affectionate toward him.

Seeing the rock star cast in the role of a TV dad with teenaged kids provided a much-needed counterbalance for a guy in danger of staggering his way into a clichéd final chapter of a rock ’n’ roll story.

Now, at 67, he’s appearing in a British TV series with his son Jack, visiting famous English monuments, and he signed on for a cameo appearance in the re-boot of “Ghostbusters.”

He may never be a menacing figure again, but he has become a sympathetic one.

His lineup for Voodoo will be a one-time thing. He has done other Ozzy and Friends shows, and has one planned for Japan later this year with Morello, Jane’s Addiction’s Dave Navarro, and former Ozzy lead guitarist Zakk Wylde.

Part of the appeal of each of his guests is musical, but part is personal. Each, he says, is a good hang.

“I haven’t come this far up the road to play with people who give me a hard time,” Osbourne said.