Nathan Fillion

When is a premiere not a premiere?

When it’s called a Masters of Horror Special Screening and the great names of the genre - including Tobe Hooper, Joss Whedon, Forrest J. Ackerman, Sid Haig, Andrew Bryniarski and Don Mancini - arrive on the red carpet to watch a slimy slugfest between wormy parasites and their disintegrating human hosts.

The nonpremiere of "Slither" on Thursday at the classy Vista Theatre in Los Feliz/Silverlake was definitely homage to the gory and gruesome horror genus.

"I’m paying tribute to the movies I grew up in the ’80s and ’90s with this in-your-face body horror flick," said first-time director James Gunn, who wrote "Dawn of the Dead," as he munched on Latin cuisine at the after-party at Malo. "Tobe Hooper just told me he loved the movie. That made my night."

"Slither," which opens on March 31, will certainly boost the horror-ible reputations of Nathan Fillion, Elizabeth Banks, Brenda James and Michael Rooker, whose expanding, blobby character resembles an insatiable Jabba the Hutt on an eating binge.

"I hope the horror genre community will embrace me, because I’m a great fan," said Banks, who repeatedly watched "Poltergeist" when she was growing up. "Please don’t tell them that storms scare me and I freak out in cemeteries."

"I’m wondering if the ’Firefly’ sci-fi cult will cross over to watch me do horror," added Fillion, who has an active following called the Browncoats. "If they do, maybe I’ll take them into Shakespeare next."

In fact, Fillion’s got a good shot of expanding his fan base.

"The sci-fi and horror communities are actually part of the same amorphous blob," said Whedon, who’s working on the fantasy script for "Wonder Woman." " ’Slither’ is a metaphor of what we’re all about, and horror fans will eat Nathan up."

So will Jabba.