WHO IS THAT MASKED MAN?

Has Jason--the unstoppable villain of the “Friday the 13th” films--finally been unmasked?

Nah. It’s just the latest PR shot of Alice Cooper--playing peek-a-boo with the maniacal Jason’s mask. Why? Turns out the shock rocker has three songs--including “He’s Back (The Man Behind the Mask)”--in “Friday the 13th Part VI: Jason Lives.” The Paramount pic opens Aug. 1.

In fact, reports a rep for exec producer Frank Mancuso, the killer’s been played by a different actor in each of the six slasher sprees.

But a spokeswoman for MCA Records, now hyping Cooper’s latest album, was quick to point out that Jason’s been on the loose for six years--and Cooper hasn’t been on the recording scene during that period. . . .

“Who knows what Jason really looks like behind that mask?” she asked. “Uh-oh, did I say that?”