(CBS/AP)-- Even on "Sesame Street," where everything is famously A-OK, problems can arise for its residents.
And that includes the Muppets. Cookie Monster grapples with an eating disorder. Oscar the Grouch gets cranky. Mr. Snuffleupagus gets the blues.
But Elmo seemed immune to any of that. Since enjoying his breakout success more than two decades ago, the 3 1/2-year-old red monster has radiated good cheer, love and trilling giggles. No wonder everyone - adults as well as children - adores him.
The key to Elmo is "his innocence, his positiveness and his sweetness," according to Kevin Clash, the man who created him and once told The Associated Press, "I would love to be totally like Elmo."
Now Clash has been scandalously separated from Elmo and from "Sesame Street," the TV series where he reigned behind the scenes for 28 years.
Clash spoke of "personal matters" as the cause of his resignation Tuesday after an unthinkable nine-day stretch that began with an unnamed man in his 20s claiming he had sex with Clash at age 16. That allegation was quickly recanted. But then came another accusation of sexual abuse, and a lawsuit.
Kevin Clash, Elmo puppeteer, resigns from "Sesame Street"
"Elmo" accuser recants sex abuse claim against puppeteer Kevin Clash
"I am deeply sorry to be leaving," said Clash in his parting statement, "and am looking forward to resolving these personal matters privately."
But privacy may no longer be possible for Clash, the 52-year-old divorced father of a grown daughter who acknowledged last week that he is gay. Singleton's lawyer, Jeff Herman, said he has been contacted by two other potential victims of Clash and expects additional legal action.
At a news conference Tuesday, Singleton said he and Clash met on a gay chat line and then, for a two-week period, they engaged in sexual contact, though not intercourse. Sex with a person under 17 is a felony in New York if the perpetrator is 21 or older.
Singleton said he didn't know Clash's profession until years later, when he Googled the man's name.
"I was shocked when I found out what he did for a living," said Singleton.
Now that career has ended for Clash, who, in his dream job as a puppeteer for "Sesame Street," was assigned a little-used puppet now known as Elmo, then turned him into a star. In the process, Clash won 23 daytime Emmy awards and one prime-time Emmy. He published his 2006 autobiography, "My Life as a Furry Red Monster," and was the subject of the 2011 documentary "Being Elmo: A Puppeteer's Journey."
Elmo overshadowed Big Bird and other "Sesame" Muppets in popularity and screen time, while marginalizing the cast of live actors. Since 1998, he has had his own show-within-a-show on "Sesame Street" in addition to appearances elsewhere in the hour.
He is also a major moneymaker for Sesame Workshop, the New York-based company that produces the show, and for licensees. At his merchandising height in 1996, he inspired the Tickle Me Elmo doll, which became a cultural phenomenon and that Christmas season's hottest toy.
This year's Elmo dolls, "LOL Elmo," which giggles, and "Let's Rock! Elmo," which sings and comes with a microphone and drum set, haven't made any of this year's hot toy lists. Even so, Elmo toys probably account for one-half to two-thirds of the $75 million in annual sales the "Sesame Street" toy line generates for toy maker Hasbro, estimates BMO Capital Markets analyst Gerrick Johnson.
Johnson said he wasn't sure how this week's news might affect sales of Elmo toys this holiday.
"How many people are going to want to explain to their kid why they're not getting an Elmo?" he asked.
On Tuesday, Hasbro issued a statement saying "We are confident that Elmo will remain an integral part of Sesame Street and that Sesame Street toys will continue to delight children for years to come."
Despite his resignation, Clash will remain an integral part of "Sesame Street" for the foreseeable future. Taping of season No. 44 will wrap by mid-December and will begin airing next September, according to someone close to the show who spoke on condition ofanonymity because the person was not authorized to publicly discuss details of its production. That means new episodes with Clash performing as Elmo will presumably continue well into 2014.
As for who might take over as Elmo, other "Sesame Street" puppeteers were already being trained to serve as Clash's stand-in, Sesame Workshop said. It's part of an understudy policy being adopted for all the major Muppet characters.
But no one knows how Elmo will fare going forward. Will the jokes spurred by Clash's downfall leave a lasting mark on Elmo's image? Will there be parents who see him tainted by association with the man who brought him to life?
In the wake of a personal tragedy that may still be unfolding, Elmo's innocence, positiveness and sweetness will be put to the test.