"In everyone's life there is a turning point," said Ken Hakuta, with a dead serious look in his eyes. "It became so clear to me one day that if I was going to take one big gamble in life, this was it.

"It was on this guy right here," said Hakuta, 36, sitting in his Northwest "toy lab," holding in the palm of his hand a red rubber, octopus-shaped creature called a "Wacky Wallwalker."

"I went to my banker and I said, 'Tom, I got this terrific idea.' I showed him a Wallwalker and I told him I needed $300,000. He was unimpressed."

That was in 1982. Today, after buying exclusive rights to the toy, setting up his own factory to turn out the critters and selling 150 million Wacky Wallwalkers, Japanese-born Ken Hakuta, a.k.a. "Dr. Fad," is a millionaire.

He is also a graduate of Harvard Business School, a casual man who turned down high-paying jobs with Fortune 500 companies and never looked back.

"It was very enticing to become a yuppie, but I didn't want to do that," he said, standing in his lab-office at 2440 Virginia Ave. NW, surrounded by toy prototypes, his personal collection of famous toys, including a Slinky, a hula hoop, Barbie and Ken, and, of course, glow-in-the-dark Wacky Wallwalkers scattered about the room.

He often greets visitors wearing a shirt with Wacky Wallwalkers sewn all over it. On this day he instructed two visitors to "come here a minute," leading them into the bathroom, where he turned off the lights so they could watch the Wallwalkers on his shirt shimmer and glow.

For effect, he slammed a few of the synthetic rubber creatures against the mirror and they wriggled down the glass, a slight movement that has delighted millions of children and made Hakuta a wealthy man.

Because of his success, he has become a consultant to fad inventors. People call his hot line (a Mickey Mouse phone) from all around the country to ask advice and talk about their inventions.

An unemployed New York writer called, then sent his fad, a Doberman pinscher mask to be used to disguise small cats and dogs as ferocious watchdogs. A woman called about "fat dolls," someone offered glow-in-the-dark Frisbees and a woman wanted advice on marketing antique dirt. Packaged inventions arrive daily.

Hakuta graduated from Georgetown, where he majored in business, before going on to earn an MBA from Harvard in 1977. His first and only job was at the World Bank in the District, "a very serious job as assistant project evaluation officer," he said. "I would go to places like India or the Sudan to look at billion-dollar power projects."

Later he opened his own import-export business, renting a desk and phone in a friend's downtown office for $100 a month. "What a pioneer I was. I was the first person to export Teflon-coated ironing board covers to Japan," he said, laughing.

Then for Christmas of 1982 his parents, who live in Tokyo, sent his children some spider-shaped creatures, which would become the predecessors of the Wallwalkers. While the kids were delighted with the toys, Hakuta was ecstatic.

"I started taking them around to people's offices and to restaurants," he said. "In restaurants I would slam them against the walls and people would go berserk, stop eating. It was good marketing research."

In the midst of research, he and a group of friends were thrown out of a Los Angeles restaurant when they tried to throw fistfuls of Wallwalkers against a wall behind Johnny Carson, hoping to capture his attention and a spot on his show.

But Hakuta maintains it was clear that the Wallwalker was his turning point, so he invested $150,000 to import the rubbery critter from Japan. He and his wife would package the toys while they watched television. Business grew, and he estimates that once he had "six houses filled with friends and their children in D.C. packaging Wallwalkers."

After newspaper stories, television appearances and radio guest spots around the country, orders started coming in faster than Hakuta could fill them.

"It was crazy," he recalled. "At one point we had three limousines waiting in the back alley behind our house to see me, people wanting to do deals."

Eventually, he set up a factory in Korea to manufacture the toys.

Last January Hakuta held what he calls the "first ever fad fair for dreamers of the world" in Detroit, inviting some of his hot-line callers to come and show their inventions to the public.

"Some people ask, 'Why Detroit?' " said Hakuta. "I like things that don't go together. You could argue that Detroit is the untrendiest city. But I figure if you held a Los Angeles Fad Fair, well, that's redundant."

In a way, the fair was Hakuta's gift to fad people, a group few people can understand, he said.

"There are conventions for people with serious, boring inventions, but fad inventors need help," he said. "You need someone to talk to.

"You just can't tell your friends you're going to invent a pet rock and mortgage your house to pay for it," said Hakuta. "It's embarrassing . . . risky mentally. Your friends think you're crazy."