LOS ANGELES -- "So Dr. Leech gets up on the bed ..."

Shoulders hunched forward, body quivering with maniacal tension, John Kricfalusi pounces atop the spindly couch in the bowels of the Spumco animation studio. "He grabs Ren like this and Ren goes AAAAAGGHH!" The cartoonist shakes his fists. His torso ripples spasmodically. His eyes scrunch up. His lips peel away from his strong white teeth to the point where you halfway expect his face to fold back over his skull. The yelping rattles the cables of the upright piano against the wall as he continues his rant:

"And he sucks all the blood out of him! Ha! 'Tastes fine to me,' Dr. Leech says. 'I can't find a damn thing wrong with it.' Then he walks out the door going 'slosh, slosh, slosh.' I loved that gag!"

Alas, it was not meant to be. Those squeamish network executives. "The Ren and Stimpy Show," Nickelodeon's very bizarre and very popular cartoon series featuring the misadventures of a downtrodden and grotesquely distorted dog and cat, would have to do without that gag. But although the show's creator may have lost one battle, he has clearly won a larger war to expand the limits of animation, both in terms of style and content, emerging as one of the field's most creative voices in years.

For this, John Kricfalusi (pronounced krick-fa-loosi) was not a likely candidate. A renegade who's "been fired from every studio I've walked into or out of," he'd come to consider himself unemployable, his visions too twisted for the bland standards of contemporary cartooning. Ren, the apoplectic Chihuahua who sounds like Peter Lorre on laughing gas (actually the voice of his creator), is given to spasms of tooth-gnashing rage, the capillaries in his eyeballs dilating to the bursting point. Stimpy, the fatuous ham-shaped feline with a detachable bulbous nose, is happiest emitting squeals of flatulent delight while lolling in the gritty splendor of his cat box and retching up hairballs. Throughout their follies is a fixation on a full range of excretory processes, complete with sound effects -- tears, sweat, saliva and other digestive juices -- and, yes, the more primary functions to boot.

It's no wonder that the four major networks slammed the door in Kricfalusi's face. And no wonder that today, millions of fans are salivating for the 13 new "Ren and Stimpy" episodes Kricfalusi is working feverishly to deliver (the first airs Saturday at 9 p.m. on cable's Nickelodeon). And no wonder too that the faithful, whose passions have been building exponentially on the basis of reruns of the six original installments, are reciting this oath (from an early episode):

"I do hereby promise only to watch 'The Ren and Stimpy Show,' to make under-leg noises during the good scenes, to wear unwashed lederhosen every single day of the rest of my life."

Drawing on His Past

It's a Saturday afternoon, and Kricfalusi is sitting -- when he's not bouncing -- in a tiny rear lounge of his Spumco studio in Hollywood, a cluttered affair with guitars propped against drafting tables, its walls pasted with tattered animation cels and other curiosities, such as a poster advertising "Liquid Bacon." Spumco -- named for the presumably mythical Dutch animator Raymond Spum, whom Spumco lore places as an escapee from debtors' prison, and the unwitting victim of a nefarious Walt Disney, who purloined his groundbreaking animation technique, then ... oh never mind -- was formed by Kricfalusi with collaborators Jim Smith and Bob Camp after Nickelodeon went out on a limb a couple years ago and commissioned "The Ren and Stimpy Show."

Now Kricfalusi peers through the heavy frames of his black cat-eye glasses, searching eagerly for signs of his visitor's unraveling. He is a handsome man, trim, with chiseled features, a neat beard and prematurely silvering hair dolloped with streaks of light brown. In tight white jeans and gray cotton sweater, he resembles an updated version of a well-scrubbed beatnik.

It takes about five minutes to gather that this man must have made a lot of teachers miserable. He runs on nothing if not the heavy fuel of pre-pubescent rebellion. He hated school, he says. Nothing to learn. He withdrew by drawing cartoons. Was he a discipline problem? "I'm a discipline problem now! Nobody can discipline me! I can't discipline myself. I can't discipline the guys in the studio!"

For Kricfalusi, it seems, all the world's a classroom, and teachers are the enemy, the all-purpose fun-spoilers. Today, teachers come in the form of network executives. Although he finds the Nickelodeon people more open-minded than most suits, he is relentless in his ongoing crusade against them to "keep the gross stuff in there."

Grossness, of course, is an integral part of the "Ren and Stimpy" philosophy. "I said in the beginning, 'Look, if I were a kid, what would I want to see that nobody will let me see? Gross stuff!' That's totally in there for the kids."

Whether in spite of or because of such attributes, Ren and Stimpy are probably the first cartoon characters since Tex Avery's Bugs Bunny and Chuck Jones's Road Runner to throw caution to the oft-broken wind, assuming in its viewers not only a high threshold for non sequiturs and a secret delight in toilet humor, but also a robust capacity to suspend disbelief. In a strange way, the show treats its viewers as equals among insiders.

Inside what? Deranged silliness. Consider the satiric commercials for such products as Powdered Toast, or High Fashion Log for Girls (a log with makeup and hair you can comb), or Stimpy's proud displays of magic nose goblins (that's "boogers" to you), or the revelry of Yak Shaving Day (leave a bowl of shaving cream and a razor by the sink; the yak will shave himself while you're asleep).

"Fur ball for fur ball, 'Ren and Stimpy' is the funniest cartoon on TV," says Matt Groening, whose own show, "The Simpsons," is no slouch in the laughs department. "With almost all animation on TV, you can tell what the boundaries are, and Ren and Stimpy repeatedly step over those boundaries. Other than 'The Simpsons,' it's the only good cartoon on TV since 'Rocky and Bullwinkle.' "

Designed for children, "Ren and Stimpy" became a runaway hit after it was introduced last August, doubling Nickelodeon's Sunday morning ratings among children ages 2 to 11, with a 5.8 rating amounting to about 1.2 million viewers. The show also has won a fanatic following among adults, especially after it was picked up evenings by MTV, Nick's sister network. However, the show will run exclusively on Nickelodeon in the fall.

The cartoon has spawned a computer bulletin board network in which correspondents engage in near-Jesuitic discussions of "Ren and Stimpy" esoterica, including hidden meanings. Recently, 3,000 fans, ranging from housewives to skinheads, turned out for an autograph session at a Los Angeles comic book store and kept the show's animators busy signing and drawing on T-shirts and fliers until 10 p.m. "Ren and Stimpy" T-shirts are selling at a rate of 100,000 per week (for $50 in Japan), with "Ren and Stimpy" mugs, comic books and a video game soon to follow. At least a half-dozen unofficial fan clubs have popped up around the country, and at such campuses as the University of New Hampshire and the University of Massachusetts, fraternity and dorms hold regular viewing parties.

The show's success is part testimony to the blandness of most everything else, but also to its own bizarre originality. Where fisticuffs and verbal abuse remain banished from the tapioca Utopia of most contemporary cartoon shows, Stimpy and particularly Ren fairly seethe with the comedy of aggression. Muddling their way through an all-too-malevolent universe, they bash and are bashed, stomp and are stomped, are subjected to grotesque transmutations and cubist-style facial realignments. That in itself may be nothing new in the realm of cartoons, but the denizens of "Ren and Stimpy" bring new extremes of emotion: rage, paranoia, naked greed, even psychosis, all of which give the show a uniquely contemporary feel.

And such name-calling. As the guileless Stimpy chants, "Happy, happy! Joy, joy!" his best friend Ren may screech something like "You bloated sack of protoplasm!"

The background music, ranging from prissy classical arias to cheesy jazz, chimes in ironic counterpoint to the visual hysterics. While the cartoon often luxuriates in the atomic imagery of "The Jetsons," with the attendant kidney-shaped furniture, its real mind-set is postmodern disjointedness. For instance, Ren's last name is Hoek, presumably Dutch, but he speaks in a broad Mexican accent.

"Ren and Stimpy" also distinguishes itself as the only children's cartoon series ever to kill off its main characters every few episodes. The two are devoured by space monsters composed of giant gobs of brain tissue. Stranded on a black hole, they experience death by implosion. And their very existences are wiped away without a trace when Stimpy pushes the forbidden "history eraser" button on the console of their spacecraft.

For Kricfalusi, that's half the fun. "I love killing off my characters!" he says, voice charged with glee and defiance. "You might as well abuse them as much as you can, 'cause in real life you can't take that much abuse. You'd like to give somebody that much abuse, but in a cartoon you can get away with it. So let's DO IT!"

Symptoms of 'Fire Brain'

Personal details about the cartoonist are tough to come by, though it's hard to tell whether this circumspection arises out of a private nature or an unwillingness to hold still long enough to go over them. His age? "Thirty-six." Straightforward enough, but ...

"The manliest age!" he effuses. "I couldn't wait to be 36! Thirty-six is how old Kirk Douglas was when he was born! And he's still 36 years old!"

As he shuffles uncomfortably in his seat, paces the room, stares at the ceiling, goes for more coffee, this much comes out:

The name is Hungarian, or possibly Lithuanian or Ruthenian -- Kricfalusi isn't really sure. He says his father keeps changing his mind. Kricfalusi himself is Canadian. His grandfather was an Eastern Orthodox priest who emigrated from Ukraine when Kricfalusi's father was a toddler. Kricfalusi, raised in Ottawa, always drew cartoons; he started by re-creating the entire Hanna-Barbera catalogue, then graduated to drawing Betty and Veronica of the Archie comics in "dirty outfits" that he hid in the basement so his parents wouldn't find them.

In 1979, freshly kicked out of college, he came to Los Angeles "to get fired from animation." He worked for, and was sacked by, a variety of studios. His credits include directing "The Jetsons" and supervising "The New Adventures of Mighty Mouse."

Kricfalusi may lack discipline, at least the conventional variety, but he is nonetheless clearly driven.

"John has what he calls 'fire brain,' " says partner Bob Camp, who writes and directs his own episodes. "There's so much going on in his head that he can't relax. He has to make cartoons or his brain will explode.

"I think he's more at the mercy of his brain. ... He's a victim of his own genius. He was smarter than anyone he'd ever worked for, and he was sick of doing crap."

Camp has won Kricfalusi's respect, and with it, a large degree of autonomy. "Fortunately, he leaves me alone," says Camp, who wrote and directed "Stimpy's Invention," in which the well-meaning cat designs a "Happy Helmet" for Ren, resulting in a wild psychotic episode. "When you're under John's thumb, you know it."

These days, Kricfalusi is feeling the strain of assembling the 13 episodes ordered by Nickelodeon. Each episode takes 10 to 11 months to complete (though the studio works on a number of them simultaneously). The process harks back to the golden years of animation, when teams of artists created stories, drawings and dialogue, with sight gags ruling above all else. The word "script" is, to Kricfalusi, fundamentally anti-animation. Brief story outlines, devised over dinner or drinks in neighborhood restaurants, are translated to scenes on storyboards, and later rounded out in raucous gag sessions.

For the new season, a number of episodes will be fleshed out to a full 30 minutes, a departure from the eight- to 11-minute vignettes that typically fill out a half-hour show. The animators were encouraged to "start opening up the personalities more," Kricfalusi says. "Then we started going crazy, like we'd put on the Happy Helmet."

Given his manic tendencies, it isn't surprising that Kricfalusi supplies the voice of Ren. "Nobody else could get the right feeling of psychosis that for me comes naturally," he says. "Ren needs to have several personalities living inside him. And I was the only one who could do it."

According to Camp, Kricfalusi put off learning to drive until recently. Every time he got behind the wheel, Camp recounts in all earnestness, Kricfalusi would see "the Little Man."

The Little Man would haunt him to the point of distraction. Kricfalusi could hardly stay on the road. The Little Man turned out to be Elmer Fudd.

To hear Kricfalusi tell it, some of Ren and Stimpy's finest moments have died on the storyboards. Even at the relatively permissive Nickelodeon, he's not happy unless he's testing the limits. (The show's plot and gag lines are edited during the storyboard stage, before the animation process begins). Usually, the scenes that get cut involve heroic exchanges of bodily fluids -- or, for that matter, entire organs -- that executives are inclined to interpret as having sexual overtones. In this, they're usually mistaken, says Kricfalusi. "It's not sexual. It's just plain gross."

For instance, take the sequence cut from an upcoming episode in which Ren's cousin, Sven, unwittingly jabs a fork into his own elongated tongue instead of the pork chop on his plate. "Lom, lom, lom," Kricfalusi says, affecting the sound of mastication. "Stimpy looks at it and asks if he can have some. So Sven puts the fork in his mouth and pulls out his tongue and hands it over to Stimpy and Stimpy takes the fork and shoves Sven's tongue into his mouth and starts swallowing it. And the whole time, they're being pulled closer toward each other because Stimpy is slowly swallowing Sven's tongue! They thought that was sexual, which it wasn't in the least. It's just a stupid joke. It had nothing to do with kissing. Whatever the joke's really about, they think it's about something else."

"I'm always prepared for the most bizarre," says Vanessa Coffey, Nickelodeon's vice president of animation, who launched the show into development after Kricfalusi pitched her an early version called "Your Gang," in which Ren and Stimpy were peripheral characters. "My job is to pull him in when he needs to be pulled in. He has off-the-wall ideas that are sometimes absolutely shocking -- you just can't even believe that he's thinking that way. I think 'Ren and Stimpy' will be a classic. We're not in this for the quick hit, like networks. We're in this to build a library that will be with us for 10 or 15 years."

No Deep Secrets

Kricfalusi goes for his third cup of coffee and fields a suggestion that part of the show's phenomenal success in some part may reflect the country's Zeitgeist: anxiety, economic hardship, suspicion and fear. This, along with other existential speculations about the relationship of Ren and Stimpy, Kricfalusi shrugs off with withering disinterest.

"There's nothing modern about being small and sticking together through the face of adversity," he says impatiently. "That's man's history. There's always rebellion against authority. Everybody feels oppressed all the time in any society. Ren and Stimpy buck authority. We have feelings and emotions and somebody else won't let us express them. Well, Ren and Stimpy express them. If the show has a message, that's what it is."

Sweet rebellion. It infuses every brush stroke of the show. "This whole studio is built up of guys from other studios who couldn't get along with anybody!" Kricfalusi roars. "This is the meanest bunch of bastards you've ever seen in your life. Nobody listens to anybody here."

Predictably, viewers have come up with any number of interpretations of the characters' relationship, including a fair number of letters asking if they're homosexual. Kricfalusi rolls his eyes dismissively. "How would you describe the relationship between Ralph and Norton? I mean, one's {a jerk} and one's retarded. It's a classic combination."

The character of Ren, he says, was inspired by a postcard of a Chihuahua in a sweater. "Chihuahuas are just these little weird hideous creatures that scream at you, and old ladies think that they're adorable. I always thought that was funny: this disgusting little hairless monster that would gladly murder you if it had the power, and everybody wants him to wear a sweater while he just wants to tear your skin off."

Stimpy's genesis was simpler. He started as a doodle, was named for a college friend and quickly evolved as a foil to Ren's tantrums.

But anyone looking for a "back story," or a secret biography that might somehow explain their erratic action, will be disappointed. "I hate that, when they start explaining everything!" Kricfalusi grouses. "Look at 'Tiny Toons.' They explain why they're funny, for Chrissake! They go to the Acme Looniversity to learn to be funny. I mean, that's such a misunderstanding of the whole spirit of Warner Brothers cartoons. For the past 20 years in animation, it became so conservative that nobody could trust the humor. We assume that the audience isn't that stupid. We assume that if we give them a joke, they'll laugh. And you don't have to spend four hours explaining every little joke.

"Watching television used to be an event," Kricfalusi goes on. "You didn't just sit in front of TV all day long like a zombie. You had your own special shows, and getting ready to watch them involved a whole ritual ... and when you were a kid watching a cartoon, you actually enjoyed watching the commercials. Huckleberry Hound would actually come out and try to sell you cereal. I loved it! With 'Ren and Stimpy' I wanted to give kids a sense that this was an event."

And there were souvenirs -- Kricfalusi wouldn't eat his cereal in the morning without his Huckleberry Hound bowl and his Yogi Bear mug. If one wasn't clean, he'd keep after his mother until she cleaned it. And then, to cut the Yogi Bear mask off the back of the cereal box. As he recalls this, his eyes light up with childlike joy.

Talking to Kricfalusi, you come away with the impression that, somewhere back in his childhood, he experienced a moment that transformed him forever, a moment of such transcendent bliss that he would spend the rest of his life trying to re-create it. That moment would have come watching cartoons. You can see it in all kinds of ways, but you can especially see it in the way he becomes electrified when he flips through the pages of a storyboard, acting out all the parts, thrashing, jumping, stomping, screaming at the top of his lungs -- as he is doing now, recounting the upcoming episode called "Ren Gives His Love" (Ren joins an organization called "Fake Dad" and takes on the care and feeding of a brutish felon named Kowalski).

"Back off, man! All right, Kowalski! Take him down! Take him down!" Kricfalusi shrieks in the voice of Ren, slashing at the air with a wooden pole he's adopted as a prop, the better to simulate Kowalski's spanking. Nearly whacking a visitor upside the head, he trades the pole for a hairbrush, which in the heat of the performance is no less menacing.

"And here come Kowalski's big meaty thumbs, and he jams 'em into the back of his pants! And he starts to pull 'em down!!" And then Ren sees what no one should ever see: "The tip of the crack in his ... BUTT!!!"