Most peoples heads are up their ass. But some of magician Roy Horn’s head rests in his stomach.

According to the N.Y. Daily News quoting The Star, doctors performed a radical operation to save the life of mauled tiger trainer Horn, cutting away part of his skull and storing it in his stomach.

A source told the Star tabloid that Horn is paralyzed on his left side and that his condition is far worse than friends have portrayed.

The flamboyant entertainer – who lost massive amounts of blood from a severed artery – suffered two strokes and flat-lined on the operating table for almost a minute, the Star said.

“Roy has been fighting like mad to stay alive,” the source was quoted as saying. “Anyone else would have died by now.”

MGM Grand/Mirage spokesman Dave Kirvin said Horn is still in critical but stable condition, but declined to be more specific.

The University Medical Center which is treating Roy referred all calls to Kirvin.

Roy’s life may have been saved when doctors performed a radical procedure called a hemicraniectomy on Oct. 4, the day after he was mauled by a tiger at the Mirage during a live show, the Star said.

The operation involves cutting away a C-shaped section of skull on the side of the head to alleviate pressure from brain swelling.

The skull fragment was implanted in Horn’s abdomen for safekeeping, to keep the bone marrow alive.

“It is amazing – and we see immediate improvement in some of the patients,” Dr. Joshua Bederson, a neurosurgeon at Mount Sinai Medical Center, told the Daily News.

Horn may be able to recover from the left-side paralysis, Bederson said.

“Frequently someone like that will regain a tremendous amount of function, including the ability to walk, drive, and return to work again,” he said.

Montecore, the 600-pound white Siberian tiger that attacked Horn, was released from a 10-day quarantine yesterday after showing no sign of rabies.