Happy 25th birthday, Jason (search). Alumni of the long-running "Friday the 13th (search)" horror-flick series gathered at Universal Studios (search) for closing night of the ScreamFest Horror Film Festival and a 25th-anniversary party celebrating all things Jason Voorhees — that hockey mask-wearing, machete-wielding, mass-murdering central character of the 11 low-budget films.

"It's 25 years later, and it's wonderful," said series producer Sean S. Cunningham.

The Saturday night gathering also marked the unveiling of the sort of item usually reserved for a higher-brow Hollywood party: a glossy, lavishly illustrated, hardcover coffee-table book, "Crystal Lake Memories: The Complete History of Friday the 13th," by entertainment reporter Peter M. Bracke.

With a young actress on his arm — screaming, of course — an actor in a Jason costume was treated to "Happy Birthday" sung by many of the performers who'd played Jason's victims.

After being asked to cut the first piece of his birthday cake, "Jason" whipped out his machete and hacked it to pieces, to the delight of dozens of cheering fans.

As alumni signed copies of Bracke's book, they reminisced about their work on the series.

"I was Jason's first victim," bubbled actress Bobbi Morgan, who appeared in the 1980 original "Friday the 13th," in which Camp Crystal Lake served as the setting for a slew of murders. "(I) had to jump out of the jeep, and run into the woods where it would be safe. And I ran, and (Jason) finally got me and he slit my throat. He got me! I never even made it to the camp."

Actress Diana Barrows appeared in "Friday the 13th VII: The New Blood" 17 years ago, and said she still gets fan response from all over the globe.

"I was in Poland two weeks ago, and I met these kids that love 'Friday the 13th,' and asked me for autographs," she said. "Fan mail from Japan. Fan mail from Australia. (I'm amazed by) the fact that it's so international."

ScreamFest's Rudy Scalese observed: "We love to hate Jason because he's one of those characters that everyone can connect with. In the beginning, at least, he was truly scary. But then he sort of became a little bit more of an icon people can cheer and root for, the same way you root for villains in one of the James Bond movies, or you clap for villains in one of those 'Fantastic Four' movies. Same thing."

And it seems Jason isn't done killing yet.

"Well, you know, it's no surprise they're actually planning another film," revealed author Bracke. "It's going to be another team-up film, with Freddy (Krueger of the "Nightmare on Elm Street" series) vs. Jason vs. Michael Myers (of the "Halloween" films), which makes sense. And then they're talking about remaking the first movie and starting all over again ...

"They'll just keep makin' them. Why stop at 25 years?"