Peter Firmin, the co-creator of Clangers, Bagpuss and Basil Brush, has died at the age of 89, it has been confirmed.
Mr Firmin also helped create other classic children's shows such as Ivor the Engine and Noggin the Nog.
He died at his home in Kent after a short illness, Clangers production company Coolabi said.
Mr Firmin received the Bafta Lifetime Achievement Award in 2014.
He leaves behind his wife Joan, six daughters and numerous grandchildren and great grandchildren.
A statement from Coolabi said: "During a career spanning over six decades Peter worked with great skill in a remarkably wide variety of creative disciplines as a fine artist, craftsman and author.
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"Of all his work he will probably be most fondly remembered for the characters he co-created and made."
Mr Firmin worked with Ivan Owen to create Basil Brush; and Oliver Postgate on Bagpuss, Clangers, Ivor the Engine, Noggin the Nog and Pogles Wood.
In loving memory of Peter Firmin.— Bagpuss (@OfficialBagpuss) July 1, 2018
11 December 1928 - 1 July 2018 pic.twitter.com/TK3aOQeDgf
In 1999, Bagpuss was voted the most popular BBC children's programme ever made.
The Coolabi statement said: "Peter continued to work with great enthusiasm on creative projects right up until the beginning of 2018, most notably on a new series of Clangers, which won a Bafta in 2015."
Floella Benjamin, who fronted children's shows such as Play School and Play Away and is now a Baroness, said all Mr Firmin wanted to do "was to create magic to stimulate kids' minds through his creative vision".
Alice Webb, director of BBC Children's programmes, said: "Peter helped to bring to life some of the most iconic children's programmes of a generation."
She described him as a "remarkable man with an incredible ability to create wonderful characters that children have adored for decades".
Fans of his work have been paying tribute on Twitter.
Robert Hanks said: "Is there anybody in Britain whose childhood wasn't improved by Peter Firmin?"
Walter Dunlop said the Mr Firmin and Mr Postgate were a "little oasis of kindness", adding: "Whenever I feel lost, scared or just in need of a little escape for a few minutes, their work will usually do it for me."
Born in Harwich in 1928, he trained at the Colchester School of Art and, after a period of National Service in the Navy, he went on to attend the Central School of Art and Design.
It was while teaching there that he met Mr Postgate with whom he formed Smallfilms.
In 2016, in an interview with the BBC at the unveiling of an exhibition of his work, Mr Firmin said of his relationship with Mr Postgate: "He wrote and imagined things and I brought them to life as pictures."
He said: "We sometimes disagreed, but generally we agreed in the end as we had the same sort of taste and, also, we both rather liked the idea of gentle stories where there was no aggression really and everyone was rather happy, gentle and content."
Mr Firmin revealed that Bagpuss, who starred in 13 episodes in 1974, was supposed to be a marmalade-coloured cat but an error at the fur-dying company saw him become pink instead.
Mr Firmin's wife Joan made Bagpuss' paws and knitted the original Clangers, while their daughter Emily played Bagpuss' owner.
Clangers first aired in 1969 with Mr Postgate, who died in 2008, providing the narration.
Mr Firmin's earlier creation, the Moon Mouse from his Noggin The Nog stories, provided the inspiration when the BBC asked him to create something set in space.
Clangers, which followed a clan of mouse-like creatures who lived on a moon, was broadcast by the BBC until 1972 with a special following in 1974.
In 2015, the series was revived on CBeebies and narrated by Michael Palin, which Mr Firmin called "exciting".
Reacting to the news that he would be presented with a Special Award at the Bafta Children's Awards in 2014, Mr Firmin said it was touching that his work was remembered with affection, decades on.
The chair of Bafta's Children's Committee at the time said Mr Firmin helped to lay the foundations of today's children's TV industry.
In recent years, Mr Firmin criticised the use of computer generated imagery on modern programmes and said there was more life in his knitted puppets.
He said: "I hate CGI faces on humans because you look in the eyes and there's nothing there. There's no soul."
Retaining the knitted characters in the new Clangers was important to him, he said, as he took on the role of design consultant and co-executive producer on the revival.
Mr Firmin said: "With high definition and the very good production, you do feel you could almost hold them now."
While the recent series cost a reported £5m to make, Mr Firmin recalled the primitive settings in which the original was created, when improvisation was the order of the day.
He said: "We had to do everything ourselves because the budgets were pretty small in those days.
"It was all very primitive then, though we didn't think it was primitive.
"I hardly ever bought any new materials. I improvised all the time, which was really the theme of the whole thing."