Howard Stern has been accused of spreading “demonic evil” by his former radio rival Mancow Muller.

The shock jock, 69, was embroiled in a bitter feud with 57-year-old Mancow – whose real name is Matthew Erich Muller – when they were rival DJs at competing radio stations in the 1990s, with Howard once threatening to “rape” his ex-nemesis.

Mancow ranted in a trailer for Vice TV’s upcoming docuseries ‘Dark Side of the 2000s’ about how their rivalry erupted as his dad John was battling terminal cancer: “My father was a $30,000 a year cabinet maker and he became the number one topic on Stern’s show for a year.

“The countdown to his death… how he was going to have sex with my mother. “How he was gonna use my mother’s saliva on himself when he raped me, how he was gonna dig up my father’s corpse – he told his listeners to go to my father’s funeral.”

Howard also once branded Mancow his “b***h” and called himself “the master vampire”.

Mancow added: “What is that? That type of demonic evil, this is wrong.”

Some of Howard’s staff at the time felt the shock jock had gone too far with his abuse.

Jackie Martling, former head writer for ‘The Howard Stern Show’, recalled the “ruthless” feud in the docuseries.

He said: “He’d start saying horrible things. I didn’t want anybody to think that this is my concept.”

Mancow admitted Howard’s team “called me and apologised” for the abuse, adding: “(They) wanted me to know, ‘I didn’t write this, this isn’t funny.’

“They would tell him: ‘Howard, you’re gonna lose them, this is a mistake!’”

Howard’s other infamous feuds have included one with comic Kathie Lee Gifford, who says he targeted her despite never meeting him.

The 69-year-old told the Today show: “Howard Stern had a feud with me going on 30 years. I never met him. I never listened to his show. He hated my guts for 30 years.”

She added about how he eventually called to say sorry and they made up: “We had a half-hour conversation.

“(Howard said), ‘Will you forgive me, Kathie, please? I’m doing some hard work on my life. I know I hurt you. I’m so sorry and I need to ask you to forgive me.’”