When Caleb Chung has a big idea, the toy world pays attention. The co-inventor of the Furby doll created a sensation in 1998 that sold 40 million of the talking furry creatures.

Now at a Bay Area start-up, he is launching a new dinosaur robot for kids that he hopes will build upon his dream of creating lifelike, emotionally responsive mechanical animals.

Chung's new brainstorm is called Pleo and it will debut this fall. He is unveiling it today at the Demo conference in Scottsdale, Ariz., and has also taken the wraps off his Emeryville-based company, Ugobe, which is making Pleo.

``People are in love with robots, but the feedback we have is people need to have a more engaging relationship with their products,'' said Bob Christopher, chief executive of Ugobe. ``They want to treat something like a pet. So we need robots that show and feel emotion and that evolve over time.''

The $200 Pleo dinosaur promises to one-up Chung's earlier creation. While Furby had two computer brains, Pleo will have seven computer brains that control 14 motors and 38 sensors. Christopher says the combination of intelligence, precision movement and personality will make Pleo a believable, lifelike pet.

``This robot is going to have organic movement, so that it seems to move and behave like something real,'' Christopher said.

In an age when robotic toys have become a multibillion-dollar business, Ugobe will have plenty of company with rivals such as Wowie's mechanical dinosaurs, Lego's Mindstorm robots and Honda's Asimo humanoid robots. Sony recently pulled the plug on its Aibo robot dogs, but Ugobe isn't worried because Sony's high-priced dogs, which cost $2,000 and up, appealed to gadget freaks.

Ugobe (a play on ``you go become'') is aiming for a more mainstream market with much cheaper robots.

``Conceptually, what they've got is very interesting,'' said Tim Bajarin, an analyst at Creative Strategies in San Jose. ``If they can deliver fluid motion and lifelike functionality and intelligence, they have something that breaks new ground and could be quite a hit in the toy market.''

Pleo is the first of a line of ``designer life forms'' that Chung and Ugobe plan to create that combine the latest in artificial intelligence, robotics, mechanical engineering and toy design. The dinosaur will have ``neural network'' software -- a program that behaves in a brainlike way as it processes many pieces of information to determine its actions.

The 3-year-old company's robots will be designed to elicit emotional responses, be aware of their environment and change behavior over time. Pleo is a baby ``camerasaurus,'' a real dinosaur that scientists describe as a Jurassic-era equivalent of a cow. Pleo will be about 20 inches long. But Christopher says it will be smart enough to walk along a table, sense the edge and turn back with a whimper and the appropriate emotional body language.

Dubbed a ``modern Gepetto'' (the creator of the puppet Pinocchio that comes to life) by Wired magazine, the 49-year-old Chung designs toys in isolation from the rest of the staff at his home in Boise, Idaho, where he lives with his wife and three daughters.

He grew up in Watsonville. His father was a psychologist and the family moved frequently. Chung became introverted and spent a lot of time ``in corners by myself taking apart toys.'' Among his favorite toys was ``Thing maker,'' which allowed him to create new plastic figures from molds.

He became a comedian and a mime before he began designing toys. In 1998, he co-designed Furby for Mattel and collected royalties on part of the $1 billion in revenues that Hasbro reaped from Furby. He continued to run small companies that designed toys for big toy companies. From the early 1980s, he dreamed of doing the ultimate child's pet.

``I've always been in love with dinosaurs because of their long necks and tails that suggest such fluid movement,'' said Chung, who talks excitedly about his creations. ``We want to create a scientifically accurate dinosaur, like the babies in ``Jurassic Park'' that hatch from eggs. Isn't that a wonderful moment as this impossible thing comes to life?''

But with Pleo, Chung decided to do a start-up that would handle everything, from the creation of the robots to hiring contract manufacturers in China to make them. Weinstein said the 25-person company has raised $2.5 million to date and will raise more money later this year. Ugobe's advisory board includes Steve Mayer, co-founder of Atari, Curtis Sasaki, a former Sun Microsystems executive, and Gordon Radley, former president of Lucasfilm.

Christopher said the company hopes to make a million units for the fall and hopes to sign up retailers to sell it at the annual Toy Fair show in New York in mid-February. Investors in the company include various angel investors, including some from China who are helping to get manufacturing deals arranged.

Ugobe's strategy as a start-up is to create products that will market themselves and thus don't need the distribution muscle of the large toy makers, Chung said.

Over time, Ugobe plans to make more sophisticated, lifelike robots. Chung said he has been waiting for improvements in technology to make possible sophisticated toys with cheaper and cheaper price tags.

While other entrepreneurs who hit it big sometimes retire, Chung says he still has a lot of fun working on new creations.

``I can't stay out of the sand box,'' Chung said. ``A legacy I would love to leave is to create a new palette for artists.''