THE fiend who ab­ducted pretty teen Elizabeth Smart from her bedroom in the case that riveted America 11 years ago has been beaten to a bloody pulp by a fellow prison inmate and is now living in fear.

Brian David Mitchell, 59, was sentenced to life with­out parole for snatching a then-14-year-old Eliza­beth from her Salt Lake City home in June 2002 and repeatedly raping her until she was rescued nine months later, say authori­ties. But now the cowardly monster is getting a taste of his own brutality.

Earlier this year, a prison source says that one of Mitchell’s fellow inmates at the high security fed­eral penitentiary in Tucson, Ariz., finally grew tired of his arrogance and fanati­cal religious ramblings and beat him into submission.

“Mitchell was well-known among the other convicts even before he arrived,” said the insider. “He thought he was a celebrity, and he acted cocky and arrogant.

“But he had a target on his back because the other inmates hate child molest­ers. It’s part of the prison code. Even murderers look down on them as the lowest of the low.”

Finally, one of the inmates lashed out in a violent rage.

“He pummeled the creep to the ground and punched and kicked him for several minutes,” said the insider. “Mitchell didn’t even fight back. He just curled up in a fetal position and cried for mercy. Meanwhile, several of the inmates were cheering the attacker on and yelling at Mitchell, ‘This is FOR Elizabeth Smart!’”

Prison guards finally stopped the onslaught, and the source says: “Mitchell definitely had the crap beaten out of him. He had a swollen eye, bloody lip and several cuts and bruises.”

The beating also brought a dose of reality to one of Ameri­ca’s most hated felons.

“Mitchell suddenly seemed to realize that his infamy didn’t impress anyone behind bars and that everyone con­siders him to be the scum of the earth,” said the insider.

Mitchell – whose wife and accomplice Wanda Barzee was sentenced to 15 years – was later as­signed to another section of the prison that houses mostly sexual offenders. And the beating seemed to scare some sense into him. He’s since cut his hair and trimmed his beard, no longer resembling the wild-eyed fanatic at his trial.

Meanwhile, Eliza­beth, who bravely faced the fiend down at his sen­tencing hearing in May 2011, is now 25 and thriv­ing. In February 2012, the attractive blonde mar­ried sweetheart Matthew Gilmour in Hawaii. She’s a contributor to ABC News and travels throughout the United States speaking to various groups about her time in captivity.

“I’m sure Elizabeth doesn’t know that Mitch­ell got beaten up in prison and most likely doesn’t care,” said another source. “She never mentions his name. In her world, he doesn’t exist.”