Hasbro is offering a special-edition Transformers figure at Comic-Con.

This summer’s hottest toys won’t be coming to a toy aisle near you. The only place to get them is at Comic-Con International in San Diego.

Since 1970, the city has hosted Comic-Con, and on Thursday, the annual comic book convention opened again, attracting an estimated 125,000 fans, many in capes and tights. And toymakers like Mattel and Hasbro, sensing an opportunity to make a closer connection with those fans, have been attending for years, offering a look at their latest toys and a peek at the ones to come.

“It’s a unique opportunity for us as a company to interact with the fans,” said John Frascotti, chief marketing officer for Hasbro.

“As a company that’s committed to that audience, we see an opportunity to provide something unique that they could not ordinarily get.”

But as Comic-Con has grown, it has pulled other entertainment industries into its orbit: video-game makers, TV producers and Hollywood studios, all jostling for the attention of the crowds in the massive convention hall.

To fend off the growing competition and better attract their fan base, toymakers started adding bells and whistles to their toys, offering bigger and deluxe versions, often in packaging with light and sound features. And because these toys could not be found anywhere else, collectors spent their precious convention time waiting in line for a chance to buy them.

Presentation matters

“For this consumer, it is really important that they have something special, something they can display at home,” said Jill Nordquist, senior director of marketing for entertainment brands at Mattel. “It really is about the presentation.”

Mattel first attended Comic-Con in 2000 with a small offering, but it has expanded every year since. This year, its largest toy is a 20-inch articulated replica of the Stay Puft Marshmallow Man from the movie “Ghostbusters” that comes with a city diorama and is packaged inside a box that resembles a suitcase. Other toys include Swamp Thing, a character from DC Universe, which includes eco-themed packaging of a paper pulp mold of the character’s head, and Blazing Sword Voltron, a version of the robot from the “Voltron” TV series, with packaging that includes a sound bite from the opening of the original series.

For Hot Wheels collectors, Mattel has two vehicles up for grabs: a replica of the DeLorean car from the movie “Back to the Future” that comes with a movie diorama, and a dairy truck in a package designed to look like a Franken Berry cereal box.

“The key difference with the Comic-Con offerings is the packaging,” Nordquist said, adding that the casual mass-market consumer would not appreciate the special features as much.

Toy companies have been cultivating the Comic-Con audience for years, said Stacy Leistner, spokesman for the Toy Industry Association, an industry trade group. Toymakers are willing to offer more at Comic-Con because it provides a prime opportunity to receive crucial feedback on top product lines.

“There is a real desire to hear from fans,” Leistner said. “The feedback they receive will be incorporated into the next generation of products.”

Mattel declined to say how much it spent on Comic-Con, but Nordquist said the niche audience that attended the convention was important to the company. “When we look at this collector, this focus is not on driving huge volume,” she said. “It’s understanding the collector community.”

To help build that connection, Mattel invites its product and packaging designers to the convention to interact with fans at panel discussions and autograph signings.

“Packaging is not just something to hold the figure,” said Frank Varela, an art director for Mattel who worked on the packaging for this year’s exclusives and will be attending the show. “Packaging enhances the experience of having the toy. It harkens to nostalgia for the fan boys.”

The nostalgia factor

Hasbro also tries to capitalize on that nostalgia. One of its biggest offerings this year is a Star Wars Revenge of the Jedi collector set, which includes 12 action figures in a box designed to look like the Death Star, the space station from “Star Wars.” (Movie buffs will recognize the name as the original title of “Return of the Jedi.”)

Other offerings in the toymaker’s lineup for 2011 include an Ultimate Optimus Prime in slipcover packaging, a 16-inch Marvel Universe Sentinel and a combination of two of Hasbro’s most enduring licenses, Transformers and G.I. Joe, in a box that includes a Cobra Commander figure that fits inside the cockpit of a Starscream jet.

Hasbro, which declined to reveal its budget for Comic-Con, has been attending the gathering since 2000, and Frascotti said the exclusive toys were considered a reward for the dedicated fans who also made the trek every year. “The people that make the trip are the core fans,” he said. “We are committed to that audience. We like to work hard to in some ways reward them for their loyalty.”

In addition to offering exclusive toys, Hasbro invites its creators to stop by and meet the fans. Last year, Peter Cullen, the actor who voices the Transformers’ character Optimus Prime in movies and television, attended a panel; this year, Dave Filoni, the director of the “Star Wars: The Clone Wars” animated TV series is scheduled to sign autographs.

“It’s all part of providing fans with immersive experiences with the brands they love,” Frascotti said.

Even smaller businesses are getting in on the act, offering their own exclusives at the convention. Companies including Action Figure Xpress, Entertainment Earth, Funko, and Mezco Toyz will be on hand.

This year, the Disney Store partnered with Funko, a maker of vinyl and plush toys, for a new line of Disney favorites. Six limited-edition vinyl figures will be available at Comic-Con, said John Balen, director for toys and hard lines at Disney Store North America. Ben Butcher, an illustrator for Pixar, is scheduled to appear at the Funko booth to sign the figures.

Balen, a Comic-Con fan himself, said he was eager for the exclusives to appear at the convention.

“Comic-Con opens up a whole new array of guests and turns them on to our new product,” he said. “The fans that attend Comic-Con are the most enthusiastic, and hopefully the word will spread.”