Some people who know all the involved parties say they understand the family's concerns, but they do not see Mr. Tartakov and Mr. Brivic as opportunists. "These are only people who have helped Daniel and supported him and try to do the best thing by him," said Jeff Feuerzeig, the director of the documentary, who spent several years researching Mr. Johnston's life. "Why shouldn't they be like Mary Boone or anyone who bought great art early on and then it became worth a lot more money later?"
At the center of all this frenzy is Mr. Johnston, 45, who seems almost completely oblivious to it. Asked recently what he thought of the Clementine Gallery and its owners Ñ Abby Messitte and Elizabeth Burke, two successful dealers who traveled to Waller (population 2,032) last September to meet him Ñ he said: "I have no idea. I've never heard of them."
Asked if he hoped to travel to New York to see his work at the Whitney, he shook his head resolutely: "I'm not in any condition to go overseas. It would wipe me out."
At his parents' house on a recent windy Texas day, he emerged from his room in dark blue warm-up pants and a burnt-orange warm-up jersey with a cigarette hole burned through the chest. It is still possible to see in him the thin, mischievous-looking musician whose picture showed up in Texas newspapers after he blustered his way onto an MTV program in 1985 and became a local hero in Austin. But he is much heavier now and looks much older than his mid-40's, with wiry graying hair and eyebrows like brambles. He is borderline diabetic and has pronounced tremors in both hands. His voice, while still strangely reedy, has been weathered by the Doral 100's he smokes incessantly.
He doesn't drive and has few chances to leave the house where he has lived for more than a decade with his father, 84, and his mother, Mabel, 83. So as he does with almost anyone who comes to see him, he suggested a trip into town. Over tacos and several glasses of compulsively sugared iced tea, he was by turns friendly, excited, petulant and distracted, sometimes all within a few minutes, as his friends warned he could be.
But in interviews over two days, he seemed acutely aware that he is viewed as an oddity, an overgrown child Ñ or as Mr. Feuerzeig puts it, "this pet of the underground." It is an image he seems simultaneously to hate and to revel in, using it to avoid any responsibilities or expectations. (At the dollar store in Waller, where Mr. Johnston asked to be taken, a reporter offered to help him pay for several bottles of diet cola, and Mr. Johnston suddenly yelled out: "Don't penny-ante me, man. I'm a rock star!" He laughed. The cashiers laughed, too, nervously.)
Mr. Johnston said he was not at all surprised that his artwork was finally becoming well known. "I never thought I'd make it with the music that much," he explained. "I thought I was going to be famous as a cartoonist. Even up to 1985, the year I got on MTV, I still thought that I was going to be a cartoonist."
He had wanted to be an artist since he was a child, worshiping comics legends like Jack Kirby with the same ardor that he worshiped Leonardo, Picasso and Dal. His reasons for wanting to be an artist, he said, were no different from those of self-respecting bohemians throughout history. "I saw all the families and all those guys Ñ even my own father Ñ working in the factories and these places, working a real job, you know? And I said: 'Hey, how am I going to get out of that? How can I escape that? I've got to be an artist. I've got to be famous.' "
While he is often described as an outsider artist, the label doesn't really fit the way it does with, say, Henry Darger. Mr. Johnston studied art formally at Kent State, near where he was raised in West Virginia, and he is still well aware of his influences, which include Duchamp.
His descriptions of art school make it clear that he was far from a conventional student. In life drawing, for example, he was much more interested in the model than in techniques for sketching her. "It was the first time I got a real look at a naked girl," he explained, his eyes widening. "Dude, I was a fan of naked ladies. I was already buying the girlie magazines. And there she was." (He later dated the model, he said.)
Mr. Johnson's art reflects this kind of visceral connection to his desires and his fears, some real and many only in his mind. The drawings, which some critics have compared to those of Raymond Pettibon, are heavily symbolic and feature his comic obsessions, like Captain America and Casper the Friendly Ghost, alongside his own creations, with names like the Frog of Innocence, the Man in the Polka Dot Underwear and a character usually meant to represent himself, a man with the top of his skull neatly excised, known as Joe the Boxer. Swastikas are a more disturbing motif, which Mr. Johnston attributes only to a fascination with World War II.
Occasionally, the work also veers into the pornographic, though his parents Ñ members of the Church of Christ Ñ discourage this and fume when they hear about Mr. Tartakov's or Mr. Brivic's selling explicit drawings.
Philippe Vergne, deputy director of the Walker Art Center in Minneapolis and one of the Whitney Biennial's curators, said he had been a fan of Mr. Johnston's for years and rejected any notion that his work was simply a curiosity born of mental illness. "I see him as an artist on the periphery of the art world, but not an outsider artist," he said. "It's impressive when you see the consistency of the work."
Like many artists, insider or outsider, Mr. Johnston grows impatient when asked to explain his inspirations. "I just make stuff up Ñ because it's easy," he said, not looking up from his tacos. But unlike many artists, especially nowadays, he seems not to care how much his work is worth, as long as his basic needs are met: cigarettes, soda, CD's, DVD's and the pop-culture detritus that fill the overflowing studio he has set up in his parents' garage, a kind of artwork unto itself.
In fact, his father now buys nearly all his drawings. "I'll make a batch of drawings and I'll sell them to him," he explained, "and then we go to the dollar store and I buy my supply of Diet Coke with the money that he gives me for the drawings."
His father and brother then sell the artwork, mostly on the Internet, at www.hihowareyou.com, and have used income from the drawings and from his music to create a savings account for Mr. Johnston and to build a two-bedroom house for him Ñ now almost completed Ñ next to his parents'. ("It's one of the greatest things that's ever happened to me," Mr. Johnston says of the house, beaming.)
But in recent years, Mr. Johnston has also sometimes circumvented his family and sold drawings directly to Mr. Tartakov, Mr. Brivic and perhaps others who have contacted him. Bill Johnston also complains that Mr. Tartakov has visited the family's house on Sunday mornings when he knows that Daniel is at home but his parents are at church.
Mr. Tartakov admits to the surreptitious visits. "I can't go when his dad's around Ñ I'd be shot," he said. But he stresses that Mr. Johnston is a grown man and a longtime friend, and he sees no reason why he should not be allowed to make his own decisions. "I'm never calling him or pestering him for drawings," he said. "He's pestering me to take them, almost."
For years, Mr. Johnston's family was little concerned with the artwork, focusing more on the music. But his brother, Dick, a computer consultant who lives nearby, says that when it became clear that the drawings could help pay for Mr. Johnston's care, the family had to become more involved.
It entered into a relationship with the Clementine Gallery in part, he said, because the gallery agreed to split its profits not only from the work provided by the family but also from that supplied by Mr. Tartakov and Mr. Brivic. Mr. Johnston's father added that with more money coming in, the family had recently hired a lawyer to explore ways to protect their interests.
"The wolves are at the door, boy," he said.
At the door at the moment, however, was his son, who has just come back into the house after smoking several cigarettes on the back porch and flicking the butts into a mixing bowl filled with them. He announced that he was tired of being interviewed and started to usher a reporter to the door. But before he left, he said, he wanted to give him a folder full of recent drawings to take with him. The reporter declined.
"O.K.," Mr. Johnston said cheerfully. "Then I'll just mail you some."

Courtesy Clementine Gallery, New York
Courtesy Clementine Gallery, New York