LOS ANGELES - Calling all superheroes, zombies, space aliens, comic-book lovers and kids of all ages: Comic-Con is here.

The pop-culture convention, which annually draws thousands of costumed fans to San Diego, began Thursday, but the die-hards (and those with weekend-long passes) got a peek at the colorful convention floor on Wednesday night.

Hundreds of exhibitors and more than 130,000 guests are expected to pack the San Diego Convention Center for the sold out, four-day event.

"The people who go through those doors, most of them are film fans and fans of pop culture, be it video games or movies or television shows, T-shirts or comic books, it's all part of this big cultural stew," says filmmaker Jon Favreau, who will premiere his latest flick, "Cowboys & Aliens," at Comic-Con. "These are people who normally interact with one another through the Internet ... Then when you finally open it up to meeting in person, it just concentrates that experience."

The blogosphere was abuzz about some of the offerings at this year's Comic-Con, where Hollywood continues to command a headlining presence.

"Captain America" played in San Diego for a full day before its nationwide opening Friday, and star Chris Evans introduced the earliest screening. "Cowboys & Aliens" held its world premiere at Comic-Con on Saturday - a festival first. Steven Spielberg and Peter Jackson are coming to the convention to talk about "The Adventures of Tin-Tin"; Sony is offering a peek at "The Amazing Spider-Man"; and the "Twilight" trio - Kristen Stewart, Taylor Lautner and Robert Pattinson - will again greet their fans at the Con.

TV-wise, "True Blood," ''Game of Thrones" and "The Walking Dead" are big draws, while new shows such as "Person of Interest," ''Grimm" and "Terra Nova" will present preview footage and introduce their casts in an aim to attract viewers before their fall premieres.

New video games were also expected to score big at Comic-Con, where players can get an early look at sci-fi shooters "Halo" and "Gears of War 3" and the latest "Batman" and "Spider-Man" games.

"Comic-Con is this incredible celebration of the arts, and the arts spans movies, television, video games - which are incredibly artistic now. It's toys, it's collectibles, it is straight comics and graphic novels," says documentarian Morgan Spurlock, who made a movie about Comic-Con and will introduce its companion photo book at this year's festival. "It is this cornerstone of pop culture that has so much influence now."