Melissa Manchester had just finished her first song on opening night of a week-long engagement at the Diplomat Hotel's Cafe Cristal in Hollywood, Fla., when she walked across the stage and spotted a broken clear plastic cup.

It had been left by Manchester's opening act, the Unknown Comic, Murray Langston, a man who has taken a simple brown bag and filled it with a career. Before leaving the stage, Langston, whose bizarre brand of comedy was too wild, too earthy and too intense for this tie-and-tux crowd, had made one last attempt at a joke. Holding the glass high, he shattered it in his hand. "Is it live," he chortled, satirizing Manchester's TV commercials, "or is it Memorex?" Having elicited nothing more than a few titters, Langston must have wondered the same thing about the crowd.

Now, some ten minutes later, the broken cup is getting the biggest laugh of the night -- for Manchester. Looking at the plastic, she shrugs and tosses it over her shoulder. "Has Murray been drinking again?" The audience, a mob partial to Manchester, finally laughs at the comedian.

Langston, downstairs in his dressing room, is oblivious to the joke. In fact, he is drinking. He and his two-piece back-up band, the Brown-Baggers, are passing around bottles of Heineken. But they are celebrating more than just another opening night; the gig at the Diplomat is Langston's first appearance on the East Coast.

After a start seven years ago on Laugh-In, a regular stint on The Sonny and Cher Show, both as comic-actor Murray Langston, and 130 bagged appearances on The Gong Show, the Unknown Comic is on the verge of becoming known. The bag-headed comedian has been offered the lead role, without the bag, in a television pilot called Scared Stiff, about a bumbling private detective. He is also close to doing a syndicated half-hour variety show that would star the Unknown Comic, with the bag.

Langston's dressing room at the Diplomat is small but comfortable with one large mirror taking up an entire wall. A large black trunk, the kind you took to sleep-away camp, sits open on the dresser, his name in bold letters painted on the front. Inside is an assortment of paper bags, large ones, small ones ("Pictures of me as a child"), some with faces drawn on, and some clothes. The two musicians sit on stools as Langston washes and takes off his sweat-drenched shirt.

"There were a lot of logistic problems out there tonight," he says talking about Manchester's confining stage. "And the crowd, the crowd was, uh, very mellow."

The comedian pulls a clean tan knit shirt over his head, looks in the mirror, rearranges his hair. He has a slight, muscular build, a strong chin and a brown mustache that makes him resemble Sonny Bono. "Half the people seemed confused, not knowing whether to laugh or not. I imagine the older folks came in here, took one look at me and said, 'What the heck is that guy doing?'"

It's question not easily answered. On stage, Langston is a hysterically funny bagged bundle of raw adrenalin, frantically moving from one side of the stage to another, arms zigzagging in all directions like erratic thunderbolts. On top of his head is a simple brown bag, two holes for eyes, one for a mouth. The patter is a never-ending, nonstop swirl of deliberately bad one-liners:

"Good evening ladies and gentleman, this is my bag, you can take it or leave it...I just flew in from Los Angeles and got air sick. Trouble was, nobody noticed...Can you guess where I buy my clothes? Sacks Fifth Avenue...I used to wear a vacuum cleaner bag, but that sucked...And now for a song. 'He ain't heavy, he's my baggie...'"

He runs around the stage, bangs his head with the microphone, pours beer down his shirt, eats a napkin, and generally goes crazy, punctuating each line with a shrill quick laugh, reminiscent of ventriloquist Paul Winchell's dummy Knucklehead.

About halfway through the act, Langston removes the bag to perform as himself. His first words are meant as a joke, but more than the comedian's face is revealed. "I can't believe," he tells the audience, "that you bought all that bag crap."

Much of the nation has. After his first appearance on The Gong show about three years ago, Langston, unemployed and broke, started a mini-national phenomenon with his bagged buffoonery. Imitators galore popped up: an Unknown Disc Jockey, an Unknown Used Car Salesman, a University of Georgia student who ran for class president (and won) as the Unknown Candidate.

In the dressing room, a musician asks Langston to autograph a poster for a friend. The poster is the Unknown Comic's ultimate bag joke. Striking a reclining pose in the nude, Langston wears two bags; one as usual covers his head, the other is positioned a bit more strategically. What makes the picture ludicrous is the bag's size: it looks like is could hold a salami.

"There you go," says Langston. "I hope she likes it."