By Sarah Tippit

SAN DIEGO (Reuters) - It was a veritable Geek Pride Day on Thursday as the 39th annual Comic-Con opened its doors to 125,000 comic book fans, many fitted out in superhero regalia, from masks and capes to Batman-themed yarmulkes.

Nearly every corner of every hall in the multilevel San Diego Convention Center was packed with the latest in comic-related books, toys, games, autographed memorabilia and movies, with long lines of enthusiasts snaking around every corner.

Exhibits at the four-day event are inspired by everything from mainstream comic book heroes like Superman, Batman and Spider-Man, to more obscure indie titles like "Milk and Cheese: Dairy Products Gone Bad" and "Rex Libris: The Wild Adventures of a Kick Ass Librarian."

At least one cavernous hall was commandeered by Hollywood executives, stars in tow, promoting their upcoming action, horror, science-fiction and comedy movies.

Waiting times to glimpse a celebrity, take a photo or grab an autograph ran five or six hours at some of the more popular attractions, though the atmosphere remained congenial.

Elsewhere, comic-related forums hosted in-depth discussions on such topics as "Black Superheroes" and the "World's Worst Cartoons." Many of the attendees themselves were very much on display, whether covered in eyeball tattoos or resplendent in costumes of their own design.

"My name is Seron Uchia," said cape-clad Sadie Feuerstein, a 15-year-old cartoon fanatic from San Diego who came with her family and dressed as her own made-up character. "I'm an S-ranked ninja from the Village Hidden in the Sand, and my character is sent to rid the world of nine-tail demons."

"I'm here to have fun, and buy comics," she added.

"I'm a dented variant," said armor-clad Tom Hutchens, 30, an IT professional from North Carolina, who was manning a booth and trying to recruit new members to a "Star Wars" fan club.

Hutchens explained that although he looks like a "Star Wars" creature known as a Mandalorian, his homemade costume is not officially sanctioned by hard-core fan groups.

So two years ago he started his own group of "colorful variants," the Mandalorian Mercs, which he said now boasts 300 members and 14 chapters around the world.

Going to multiple comic book conventions over the years, Hutchens said: "I saw all these Mandalorians who didn't fit, who couldn't get into the mainstream fan clubs. I said people need a place to go where they feel like they belong. We needed a home, man."