When you think of the word "comics," what do you picture?

Do you envision Archie of Riverdale and his madcap attempts to woo Betty and Veronica?

Or, perhaps you visualize Batman once again foiling the nefarious Joker and his latest evil plot?

While those common images embody comics for many, they also leave out the whole world of "alt comics," where you're more likely to encounter characters like "Pumpkinhead" - a villain that pees gasoline.

At this weekend's upcoming Alternative Comic Convention at 941 Theater, 941 N. Front St. in Northern Liberties, fans of South Philly-based artist Beth Heinley's "Pumpkinhead" will be treated to a showing of more than 30 underground comic artists, each with a unique story to tell.

"This is a 'no superheroes allowed' type of show," joked South Philly artist Pat Aulisio, who helped organize the Sept. 13 convention.

Aulisio and Heinley are part of a growing movement in Philadelphia that has seen artists from all backgrounds flock toward alternative comic books as a medium for complicated stories with mature themes.

Aulisio said the movement owes much to notable artists like Robert Crumb and his famous Fritz the Cat, and Harvey Pekar, a comic book writer whose exploits were the focus of the 2003 film American Splendor, named for Pekar's own independent comic book.

What makes independent titles and creators stand out from the more mainstream books, Aulisio said, is a focus on the pure art form rather than commercial success.

The extras, the accouterments, the toys, games and other stuff that fills a typical comic convention are stripped away in the alternative comic scene.

"At something like Wizard World (a yearly mainstream comic convention) you get all this extra stuff - extras from Battlestar Gallactica, old comics, toys and all that weird crap. But, you'll see none of that here," said the 23-year-old Aulisio. "The way we go at it is to just do it for ourselves. I try to just put myself out there, to a point, and find an audience of people just like me."

Aulisio works with a group of local artists in a collective called "Philly Comix Jam" and they often travel together to other alternative comic shows, like the Small Press Expo in Maryland.

But with a thriving independent comics scene based right here in Philadelphia, he felt a local show was in order.

"We thought 'Here's a group of 20 of us, why don't we have our own cool show?'" remembered Aulisio. "Then we could more or less put Philly on the map in the alt comic scene. You know, try to make Philly the place to be, as far as comics are concerned."

Ian Harker, a 30-year-old artist from South Jersey, countered Aulisio, and said there will indeed be superhero books at the upcoming convention - they'll just be highly irreverent in nature.

Last week, Harker and other members of the Philly Comix Jam released a free publication that makes a mockery of DC Comics' beloved Batman.

Called What Makes A Man Dress Up Like A Bat?, the book pokes fun at the much-loved superhero. Harker said the book's very existence acknowledges the alternative scene's roots in traditional comics, but pointed out that it also highlights the offbeat styles found in independent books.

"We're just doing this for our love of the medium," said Harker. "It's like conventional comics, but here, we're branching out into high-concept stuff. There's a smaller audience, but the potential for growth is bigger."