"American Vampire" writer Scott Snyder is having a lot of fun creating a new vampire mythology -- which means a lot of fun for us.

For proof, look no further than "American Vampire, Vol. 2" (DC/Vertigo, $25), out this month, which collects issues Nos. 6-11 of the ongoing mature-readers series, written by Snyder with art by Rafael Albuquerque. Or the five-issue "American Vampire: Survival of the Fittest" miniseries, with art by Sean Murphy, which begins next month.

What kind of vampires are in "American Vampire"? Potentially all of them.

The book asks, "What if vampires were these physiological creatures?" Snyder said. "That ... when their bloodline hits different populations, when the blood hits someone new from somewhere new, that it sometimes makes something new. ... There have been secret species throughout history with different characteristics."

Plus, "they all have different organic weaknesses, like wood causes this massive infection in the classic European kind, but wood doesn't do anything to [the American] kind," Snyder said. "They have different reactions to sunlight, different periods when they weaken. We wanted to create a fun genealogy for ourselves, almost like a big classification chart."

And in the 1880s American West, a new bloodline emerges when outlaw Skinner Sweet gets the bite from a Carpathian vampire (the familiar Dracula type).

"He's sort of almost an evolutionary leap," Snyder said. "He is much more fierce, he has longer claws, longer fangs, he's impervious to sunlight."

Sweet creates a new bloodline starting with the other major star of the series: Pearl Jones, an actress wannabe in 1920s Hollywood.

Those two characters were introduced in the first five issues of "American Vampire," which were co-written by horror auteur Stephen King, and collected in the first hardback. In Vol. 2, we meet two more members of the cast: Cash McCogan, the sheriff of booming 1930s Las Vegas during the construction of Hoover Dam, and Felicia Book, whose lawman father met a grim fate thanks to Skinner. Both end up cursed by vampirism.

But that's not all. The old Carpathian vampires are none too happy with this new breed, and want to stamp it out. Meanwhile, an organization called the Vassals of the Morning Star would be happy to see all vampires staked -- or whatever it takes to kill them.

All of this comes to a head in the second volume of "American Vampire." But the miniseries is also where Snyder expands and explains his brave new world.

"It'll take a huge leap forward in terms of the reader's understanding of where vampires came from," he said.