On the set of Barney

His fan club has 13,400 members. He gets 1,200 letters a month. With numbers like that, it's clear that Barney is one dinosaur in no danger of extinction.

The 6-foot-tall, purple "Hugasaurus Rex" and his Backyard Gang made their debut on video 26 months ago, and the Barney series has already brought in more than $3.5 million. The first three tapes each sold 50,000 copies, making them among the most popular kids' videos out today, and in November Barney's adventures will start airing on the Disney Channel's daily Lunch Box series.

Barney is a small stuffed dinosaur who is majestically Transformed — through the imagination of the kids in his gang — into a life-size creature who then transports his human gang on adventures to the moon, the bottom of the sea, and the North Pole.

This hero of the teddy bear-and-crayon crowd was invented by Sheryl Leach, 37, and Kathy Parker, 36, two ex-teachers from Dallas who were frustrated with the video offerings for their preschoolers. Neither had any experience making or marketing videos, but persuaded their former employer, the educational publishing company Developmental Learning Materials, to back the venture.

"So much of what is available is animated, and a younger child can't respond to animation," Leach says. "It's two-dimensional and flat and not real enough for a 2-year-old to relate to." So the two partners made Barney a kind of soulmate to Sesame Street's Big Bird — a character that would make kids feel safe, Leach says. And they filled Barney's gang with real kids ages 7 to 12.

In the sixth tape in the video series, Barney Goes to School, the dinosaur and his pals sing and dance around a classroom crammed with toys. "We're promoting literacy, but it's a soft approach," says Leach. "We want to support and shape attitudes that school is wonderful." A little girl named Tina opens the tape by wishing she could go to school on a Saturday. Barney grants Tina's wish and, before you can say triceratops, she and the whole gang are whisked to her classroom. Once there, they mess with fingerpaint, do a puppet show, misplace the school's pet hamster, and sing about the alphabet, shapes, the flag, and the weather ("If all the raindrops were lemon drops and gumdrops, oh what a rain that would be").

David Voss, the 22-year-old mime who plays Barney, is a genuine friend to the kids. On the Allen, Tex., set of the new video, they gathered around him, aiming their conversation between Barney's huge jaws so their pal inside could hear them. At lunch, the kids fought over who got to sit next to him, playing pretend games about a family in which he was the father and they were the children.

Because of the way the costume is designed, Voss' voice wouldn't be heard, so Bob West, 33, handles that chore. A microphone inside the costume lets Voss hear what West is saying — both when he's being Barney and when he's not.

Some of Barney's most endearing characteristics, such as his chortling, were added by West. "I'm from a radio background, and in radio you don't leave any dead air. So when something is taking longer than it should, I'll just keep Barney chuckling."

When Barney's around, kids keep chuckling too.