By the time HBO came knocking, Todd McFarlane had seen enough. He'd already sat through endless meetings with clueless businessmen who offered obscene amounts of money to make Colorforms, coloring books and Saturday morning cartoons of his No. 1 selling comic, Spawn. They couldn't have seen his books. Otherwise, why would they suggest building a kiddie industry around his central character: a slain former government assassin, a burnt-crisp corpse reanimated as a soldier in Hell's army, who often kills evildoers by pulling out their still-beating hearts? So, in his initial meeting with HBO on creating an animated version of Spawn, McFarlane cut to the chase, ready to deal mercilessly with any TV executive who dared suggest recreating Hell's baddest warrior as a kiddie cartoon. "I wanted to ask one question . . . can I say the word, "f_-?' " says McFarlane, 36, sounding like a kid telling off his parents. "If they let me do that, there's 100 other things I could get away with, too." HBO said yes. And a new animated hero was born. Household-word heroes like Superman and Batman may have a higher profile, but these days, it's Spawn who is reaching comic fans _ in numbers that publishers of more mainstream books would trade their Bat-teeth for. His innovative book already has sold in excess of 80-million copies, producing a line of more than 50 different action figures and prompting production of a $40-million film starring Martin Sheen and Tyson's Michael Jai White. Not bad for a guy who got 700 rejection letters when he went looking for his first job drawing comics. "I wanted to see if I could create a household name," says McFarlane, with characteristic bravado. "I've readjusted my goal for half the house. Mom will never get it." By "Moms" McFarlane means anyone who is offended by the mix of violence, profanity and shades of sexual content that give HBO's Spawn its gritty feel. Unfolding like a modern-day urban horror movie, Spawn _ short for Hellspawn, of course _ traces the tale of Al Simmons, a murdered assassin who promises the devil anything if he can see his wife again. In a stroke, the demon turns him into Spawn _ a soldier armed with a living costume and hellish, green eyes. But there's a catch: He was burned horribly in death, so his new body is charred beyond recognition. Unable to risk frightening his now-remarried wife, Spawn hunkers in the back alleys of a slum; his Earthly instincts spur him to oppose evildoers, but his demonic nature brings ruthless results. "A lot of people who are into the darker side of things _ heavy metal, death metal, goth whatever _ seem to be into Spawn," says Don Taylor, manager of Green Shift Comics store in Tampa. "People who are looking for kindred spirits seem to gravitate toward this book." On HBO, that dark feel translates into bloody, broken arms, dismemberment and worse for Mafia killers and hapless innocents who would dare cross Spawn's path. The first three episodes, airing at midnight on Fridays following Dennis Miller Live, unfold in a disjointed, abstract style that owes as much to the animated movie Heavy Metal as the Batman trilogy. "People have such a stereotype about animation _ they immediately think cartoons and Disney," says McFarlane, who spent a year supervising creation of the six Spawn episodes airing this season. "They're not used to seeing Silence of the Lambs, The Godfather and Seven all in one cartoon, but that's what they're getting." From Fox-TV's The Simpsons and King of the Hill to Comedy Central's Dr. Katz: Professional Therapist and MTV's Beavis and Butt-head, adult-oriented animated series are enjoying an unprecedented popularity, something that was surely a consideration when HBO executives granted McFarlane creative control over the $6-million Spawn project. "The success of those (animated) shows . . . and the look of Disney's Toy Story showed people animation doesn't have to be about children," says David Bartis, a vice president at HBO in charge of the cable channel's new, adult-oriented animation division, "and we've shown movies, like Natural Born Killers, on HBO that have gone farther (with violent content)." McFarlane approached his deal with HBO the same way he dealt with work in the comics industry, insisting on control and a sizable share of profits generated by his creative vision. That's not what McFarlane says he found during his early career at industry giant Marvel Comics, where his work reviving old warhorses such as the Hulk and Spider-Man set sales records. By 1991, McFarlane was the highest paid artist around, drawing an estimated $1-million to $2-million annual salary. A year later, tired of continual demands to soften his storytelling style, McFarlane left, taking five other top artists with him to start Image Comics. Marvel saw the value of its stock slide 20 percent in one day while Spawn went on to success in 40 countries and 16 different languages. Forbes magazine said the artist made $5-million on revenues of $35-million in 1995, with only $2-million coming from comic sales and the rest from smart merchandising. "I've had people ask me if I'm concerned the Spawn movie won't work because Barb Wire and The Phantom didn't," McFarlane says. "It's like saying The Babe didn't work so they shouldn't have made Jerry Maguire. It just means don't make bad sports movies." It has become a pattern: When Columbia Pictures wouldn't give him control of the Spawn movie, McFarlane went to independent action kings New Line. When Hasbro and other toy companies laughed at giving him control of Spawn merchandise, he founded McFarlane Toys. While other companies dilute sales with four and five different Superman or Batman comic book lines, Spawn stays true to its readers, keeping the price steady over the past five years. For McFarlane, the concept is simple: '90s readers want as much respect _ and gritty reality _ as they can stand. "People get upset that Spawn kills bad guys, but I don't understand why Batman doesn't just pop the Joker's head, sometimes," he says. "Every time the Joker escapes, he kills somebody. My guy, Spawn, stopped a child killer in the fifth issue by killing him, so who's the bigger psycho, Batman _ who puts a guy in jail he knows will kill again _ or my guy?" Times researcher Kitty Bennett contributed to this story. AT A GLANCE: Spawn airs at midnight tonight on HBO. Grade: A-. Rating: TV-M.