Sesame Street voice actor Jerry Nelson has died at the age of 78.
He passed away of unknown causes on Thursday (23Aug12).
The famous puppeteer grew up in Washington, D.C., and signed up for U.S. variety series The Jimmy Dean Show in 1965 as the man behind Rowlf the Dog.
Nelson eventually joined the long-running children's TV show Sesame Street in 1970, becoming the first puppeteer to bring beloved woolly mammoth Mr. Snuffleupagus to life, although he is best known for playing the instructional vampire Count von Count.
He also added his talents to The Muppet Show, as the man behind Kermit the Frog's nephew Robin and Gonzo's girlfriend Camilla the Chicken.
Mourning Nelson's death on the official Sesame Street website on Friday (24Aug12), producers of the long-running show wrote: "The cast and crew of Sesame Street and the staff of Sesame Workshop deeply mourn the loss of cast member and creator of dozens of Muppet characters, Jerry Nelson.
"A member of the Sesame Street family for more than 40 years, he will forever be in our hearts and remembered for the artistry in his puppetry, his music, and the laughter he brought to children worldwide... We will miss his extraordinary spirit and the joy he brought to our Street."