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 of anonymity 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.
AP Television Writer David Bauder and AP Retail Writer Mae Anderson contributed to this report.