The man who created Mr Squiggle for the ABC series of the same name has died after a long illness in Sydney.

Norman Hetherington worked initially as a cartoonist before venturing into television in the late 1950s and pursuing his interest in puppetry.

He created Mr Squiggle, the man from the Moon with a pencil for a nose, in 1959.

First intended as a temporary fill-in, his show - written by his wife Margaret and later co-hosted by his daughter Rebecca - ran on ABC TV for 40 years, ending in 1999.

Mr Hetherington died on Monday morning at Greenwich Hospital, aged 89.

The basic premise of Australia's longest-running children's TV show was children drew their "squiggles" and Mr Squiggle would use his genius and pencil nose to turn them into a drawing.

The scatter-brained Mr Squiggle would often declare "Upside down! Upside down!" and then get his female assistant - who over the years included film producer Pat Lovell and Rebecca Hetherington - to turn it around to reveal the finished drawing.

When Mr Squiggle turned 50 in July last year, Mr Hetherington told ABC News Online the world of television was a very different place when the show made its exciting debut.

"He came into the program without even an audition... that wouldn't happen today," Mr Hetherington said.

"He was given a six-week trial and he stayed for the six weeks, six months, then six years and so on.

"And we didn't always stick to the script. There was a lot of adlibbing, particularly in the drawing segment."

Mr Hetherington, who had worked as a cartoonist at The Bulletin newspaper before Mr Squiggle took over his life, said fun was always the priority.

"People would ask what age group were you aiming at and we were not aiming anywhere, we were just aiming to have fun," he said.

Mr Hetherington is survived by his wife, a son, a daughter and two grandchildren.

His funeral service is expected to be held next Monday.

Humble and innovative

Cartoonist Steve Panozzo was friends with Mr Heatherington for about 20 years.

"What I love is the fact that Mr Squiggle was born before his children, and one of them ended up hosting the show 40 years down the track," he said.

"I think that's a lovely full circle, that it stayed within the family in that way."

Mr Panozzo says there was no trickery in the show, and Mr Heatherington simply held on to Mr Squiggle's hat from above to draw the pictures.

Things looked a bit different from where he was sitting, which is partly why so many of the pictures were turned around.

"It was so out and out simple that it was innovative," Mr Panozzo said.

"The puppets - the way they were made, the different functions they had, they were all so innovative and creative."

Mr Heatherington received a Medal of the Order of Australia, as well as awards from the University of New South Wales, the Australian Cartoonists Association and the Television Association of Australia.

But Mr Panozzo says despite all the accolades, he was more down to earth than his creation.

"[He was an] incredibly self-effacing person, very humble," he said.

"He was showered with awards and accolades and requests - they even went to a science fiction convention as special guests because Mr Squiggle is considered Australia's first astronaut."