Bizarrely huge babies and smoke-breathing reptiles cavort across the stage while thousands of light-wand-waving fans scream in response to musical numbers and questions from the familiar characters here at Universal Amphitheater.
It's opening night of the touring production "Rugrats - A Live Adventure," based on Nickelodeon's wildly successful cartoon series, and the crowd is ready to interact with a stage full of "babies!" as "Rugrats" character Angelica would say.
The show is part of a rapidly growing theatrical niche somewhat derogatorily dubbed "skip and waves," which includes shows based on such familiar children's television programs as "Barney," "Sesame Street," and "Goosebumps."
It's true that big-headed Chuckie and Tommy and all the rest of the cartoon-show characters do skip and wave at the largely adoring, mostly preschool audience. But according to firefighter Paul Hill, who has brought his seven-year-old son, Wesley, they do a lot more too.
"Rugrats isn't exactly conventional musical theater," Mr. Hill concedes, but as he puts it, the show is a sort of theater prep school for preschoolers.
"Kids like to see characters they can relate to," he says as his son hums the songs he's just heard from his favorite character, baby Tommy. "This gets them ready for more grown-up musicals later on," he says.
Hill has driven nearly two hours with his child for a boys' night out that is part of a regular routine in their household. "We go to theater all the time," he says.
For those who may have a tough time imagining the "Rugrats" leap from small screen to arena-size stage, just think big.
"The biggest challenge was how to translate a show on a big stage dealing with animated babies," says executive producer Jonathan Hochwald, noting that "no matter how you look at it, we had to create a world where a six-foot-tall baby makes sense."
In order to create the necessary perspective on stage, the adult characters ride in on scaffolding and appear farther away than the children.
Solutions such as these were devised by a group that includes puppeteer Skip Mercier, who worked with the team that brought the critically acclaimed "Lion King" musical to Broadway; Mark Mothersbaugh, a former member of the rock band Devo; and choreographer Danny Herman, a protg of the legendary Michael Bennett.
Executive producer Hochwald points out that while the notion of bringing animated children's characters to life may have originated in the theme-park parades of Disneyland, the genre has evolved significantly to include full-blown storylines and musical numbers.
"We have tried to create something that is more inherently theatrical," he says.
A dad from Los Angeles, Lonnie, who has brought his four- and six-year-old daughters to the production, is enthusiastic about the dramatic value of the evening.
"It's a visceral experience that allows them to interact with their favorite characters," he says, adding that the shows help bring the children into the world of drama, where storytelling comes to life.
The two girls agree. "We love Chuckie," they giggle as they hide behind their light wands.
These arena shows are not new - Sesame Street has taken its characters on the road for more than 20 years, and Barney has been around for nearly a decade. But they have proliferated in recent years. According to The Wall Street Journal, they brought in some $300 million in 1998, nearly double the amount a decade ago.
There are several reasons for their growing popularity, says Linda Deckard, managing editor of the industry magazine Amusement Business. Baby-boomer parents wants "good, wholesome family entertainment" for their children, she suggests, and they're willing to pay for it.
They need to be. With a ticket price of $37.50, plus dinner, parking, souvenirs, and snacks, an evening at one of these productions can run to more than $200 for a family of four.
However, graduation to more sophisticated fare appears to happen at a younger age than some parents may be expecting. Ten-year-old Matt has come to the Rugrats show with his mother, Sherri, who says she bought the tickets "months ago, way before anybody else even knew about the concert!"
Although the boy clearly doesn't want to offend a mother who has gone to such effort, he says quietly, "I didn't like it very much."
"The songs were sort of baby."
Stephen Sondheim couldn't have said it better.