Celebrity Mound

Spencer Pratt extended his 15 minutes of fame Tuesday night ? by disguising himself as an old man and freaking out cast members of “The Hills.”

Pratt, 26, who was dropped from the MTV reality show last season after reportedly making a death threat against one of the producers, wasn’t invited to “The Hills” live finale at L.A.’s Hollywood Roosevelt Hotel. But that didn’t stop him from showing up and unnerving Lauren Conrad, among others.

“For someone who was such an integral part of the show, he was not even allowed at the curb. The talent are really physically afraid of him,” says one insider who attended the finale. “Lauren Conrad had a Taser in her bag.” (A spokeswoman for Conrad declined to comment.)

When Gatecrasher contacted Pratt’s publicist to ask him about his appearance, he called us to say that he had dressed up as a “crazy old man” ? in a gray wig and aviator sunglasses ? because “when your life is edited into one-minute segments” that appear in dozens of episodes of an MTV reality show, “that’s what you look like in the end.”

Pratt says he wasn’t invited to “The Hills” finale because Conrad “was in charge of the guest list, and when LC does the VIP list, you better hope you’ve been kissing her boo-tay.”

He also dismisses speculation that he was under the influence of some controlled substance. “My high is how much people hate me,” says Pratt, who also dismisses the allegation that he ratcheted up the anxiety levels of cast members.

“That’s people who are no longer relevant trying to put out negative false accusations,” he explains.

Pratt’s wingman for the evening was Emilio Masella, the ex-boyfriend of “Jersey Shore” cast member Nicole (Snooki) Pilozzi, and while the two men entertained crowds on the West Coast, the cast of MTV’s newest reality hit partied here at an unlikely nightspot: The Eldridge.

In December, Eldridge owner Matt Levine publicly declared that the “Jersey Shore” cast was not welcome at his lower East Side haunt, but that’s where they gathered to celebrate a friend’s birthday. When Gatecrasher reminded Levine of his earlier vow, the club owner, who was on the premises Tuesday night, said the party was “private” and in such cases, he is “generally unaware of guest lists.”

Perhaps, but one reveler said it was fairly impossible to ignore Jenni (JWoWW) Farley and her fiance/manager, Tom Leppolis, “yelling at each other angrily.”