If you think heavy metal rocker Ozzy Osbourne is crazy now on his hit TV show, you should have seen him back in the 1970s and ’80s — when he was totally, certifiably insane!

In those demented decades, the original Madman of Rock slaughtered 17 family cats with a shotgun, regularly beat his wife, and was virtually always under the influence of one substance or another.

The bat-biting rocker nearly killed himself with drugs and booze and wound up in a mental institution in jails and in rehab.

“The sight of homebody Ozzy on the current MTV series ‘The Osbournes’ is hilarious for anybody who knew him as the Prince of Darkness!” a British rock insider told The ENQUIRER.

“Other rockers were like Sunday school teachers compared to Ozzy back then. He’s lucky to be alive.”

The list of wild escapades, run-ins with the law and psychotic episodes from 53-year-old Ozzy’s outrageous past looks like it belongs in an abnormal psychology journal:

  • Ozzy was admitted for psychiatric treatment for several months after he went berserk, committing a sick act of animal cruelty, shooting the family’s 17 cats. His first wife Thelma came home and found him under a grand piano in a white suit with a shotgun in one hand and a knife in the other: “I was taking drugs so much I was a wreck — I didn’t know which end of the day it was,” he admitted.
  • “Ozzy came home one night in 1976, grabbed a gun and shot the pet chickens that Thelma kept in a coop in their backyard,” said another source.
  • After 10 years of marriage, Thelma divorced Ozzy in 1981. The rocker admitted that he had beat her up “big time” and that she divorced him because he had sex with all her friends.

“I don’t know what she was complaining about — I was shagging her as well!” he said.

  • Ozzy confesses he used to down FOUR liter bottles of brandy a day — “plus beer, wine, cocaine, pills and pot. I’d have beer for breakfast and work my way up.”
  • Ozzy doesn’t remember most of the ’80s: “I was an absolute nutter, waking up in jails, waking up in different beds, emptying a shotgun in my car,” he said. “I lost weeks at a time. I got drunk for the first time at 14 and for the next 29 years I was hardly ever sober.”
  • Ozzy once outraged Texans by urinating on the Alamo while dressed as his current wife Sharon: “She’d stolen all me clothes to stop me going out drinking, so I put hers on and went out and got pissed anyway!” he explained.
  • On tour in Tokyo, a drunken Ozzy staggered back to his hotel room with a Japanese groupie — forgetting his current wife Sharon was there! “I was going through me John Lennon stage, but I forgot Sharon,” he told a reporter. “The door opens, she smacks this Japanese chick on the chin, gets a picture frame off the wall and smashes it over my head!”
  • Drunken Ozzy once woke up beside a Memphis freeway needing to empty his bladder. “I struggled over to a parked car,” he recalled, “and let go all over the front wheel. A woman’s voice said, ‘When you’ve finished, buddy, put it away and we’ll take a little ride downtown.’ It was a police car and the lady cop wasn’t at all pleased!”
  • Ozzy once woke up in jail charged with attempted murder — of Sharon! She made him agree to go into rehab before she dropped charges.

“I put my fingers around her throat and strangled her, apparently,” Ozzy said, who gave up booze and drugs after the incident. “I don’t remember a thing. I could have killed her.

“But that nightmare changed me forever. Sharon saved my life. If I’d carried on I would be dead by now. I just feel blessed.”