Jerry Nelson, an American puppeteer who played Count von Count on Sesame Street and Gobo Fraggle on Fraggle Rock, has died. He was 78.

A tribute site for Jim Henson's The Muppets confirmed Nelson died Thursday, but no cause of death was given.

Nelson’s most famous puppet character was the Count, the Sesame Street citizen who teaches children how to count. As well, he gave life to Mr. Snuffleupagus and Grover’s customer Mr. Johnson.

Nelson also played Gobo Fraggle, the leader of the colourful band of creatures featured on the live-action TV series Fraggle Rock, which ran 1983 to 1987. CBC was one of the international co-producers of the hit children’s series, which was a music-filled romp that dealt with issues such as prejudice, spirituality and personal identity. Nelson also operated other puppets on Fraggle Rock.

Worked with Jim Henson, Bil Baird

Born in Tulsa, Oklahoma and raised in Washington, D.C., Nelson first began working with American puppeteer Bil Baird, who created the marionette sequence for The Sound of Music.

He worked with Jim Henson on The Jimmy Dean Show in 1965, temporarily replacing Frank Oz, and worked with The Muppets off and on throughout the 1960s.

Beginning in the 1970s, he worked full-time on Sesame Street and became involved with productions such as 1979’s The Muppet Movie and 1981’s The Great Muppet Caper.

Nelson also performed many characters on The Muppet Show, including Sgt. Floyd Pepper (the bassist of the Electric Mayhem band), Pigs in Space star Dr. Julius Strangepork, Kermit the Frog's nephew Robin and Gonzo's girlfriend Camilla the Chicken.

In 2004, Nelson announced he would no longer be operating puppets for The Muppets. However, he continued to do voice work on Sesame Street and portrayed the announcer on some Muppet productions. He continued to voice the Count up until his death.

Other film and TV credits include The Jim Henson Show, Elmo’s Christmas Countdown, Muppet Treasure Island and Muppet Christmas Carol. Nelson's voice can also be heard on the audiobook version of It's Not Easy Bein' Green.