Puppeteer Caroll Spinney, who portrayed the beloved Sesame Street characters Big Bird and Oscar the Grouch, including providing their voices, has died aged 85.
The American died at his home in Connecticut on Saturday, according to a statement from the Sesame Workshop.
It did not mention a cause of death, but said he had been living with dystonia - a muscle disorder - for some time.
He voiced and operated both key characters in the popular children's TV show until he was well into his 80s.
The statement paid tribute to "an artistic genius" with a "loving view of the world" that helped shape the long-running children's show over five decades, leaving behind a legacy that "will be unending".
"His enormous talent and outsized heart were perfectly suited to playing the larger-than-life yellow bird who brought joy to generations of children and countless fans of all ages around the world, and his lovably cantankerous grouch gave us all permission to be cranky once in a while," the statement said.
"Our hearts go out to Caroll's beloved wife, Debra, and all of his children and grandchildren."
Spinney, who met fellow puppeteer Jim Henson in the early 1960s, was later recruited by Henson to the show and went on to play Big Bird from 1969 until his retirement last year.
Speaking to The New York Times in October, he said the role was "one of the most joyous things of my life".
His long career as one of the most recognised characters on children's television saw him take Big Bird to China, be given a star on the Hollywood Walk of Fame, and be featured on a US postage stamp.
The yellow bird was also named a "Living Legend" by the US Library of Congress.
Spinney had amassed a number of awards over his lifetime, including five Daytime Emmys and a Lifetime Achievement Award, according to Variety.
He was also nominated for a Grammy award in 1976 for the Merry Christmas in Sesame Street album.
A 2014 film called I am Big Bird later documented the puppeteer's early life and his journey to joining Sesame Street.
Meanwhile, Sesame Street co-founder Joan Ganz Cooney remembered Spinney's "countless" contributions to the programme on Sunday.
She said: "He not only gave us Big Bird and Oscar the Grouch, he gave so much of himself as well.
"We at Sesame Workshop mourn his passing and feel an immense gratitude for all he has given to Sesame Street and to children around the world."