For generations of Australian children, Terry Denton’s wonderfully chaotic drawings were part of the joy of growing up. Now the much-loved author and illustrator behind some of the country’s most treasured children’s books has died, aged 76.

Denton died on Monday surrounded by his family near Melbourne, his literary agency Curtis Brown and publisher Pan Macmillan confirmed. No cause of death has been announced, although the illustrator had experienced poor health in recent years.

Best known for his extraordinary creative partnership with author Andy Griffiths, Denton helped turn the Treehouse books into an international publishing phenomenon, filling their pages with the sort of gloriously ridiculous detail that could keep a child absorbed long after the words had been read.

Griffiths paid an emotional tribute to the man who had been his collaborator, friend and partner in mischief for more than three decades.

“Working – and playing – with Terry over three decades has been an incredible honour and a pure delight,” Griffiths said.

“I’ve never laughed so hard as I did when working with him, whether in the writing room or on stage. He was a true clown and much beloved – both in real life and as a character in the Treehouse series. Jill and I will miss him greatly.”

Speaking after Denton’s death, Griffiths described their creative relationship as “a match made in heaven”, saying the pair’s differences were often what made their work together so successful.

“We would supercharge each other. I would create a structure and he’d come in and throw a spanner in the works,” he told the ABC.

“We would play with words, play with pictures, play with ideas.”

Their partnership began long before the first Treehouse appeared. Denton and Griffiths worked together on the Just! series from the 1990s before launching The 13-Storey Treehouse in 2011.

What followed became one of the great success stories of Australian children’s publishing.

Across 13 Treehouse books, Andy and Terry’s fictional alter egos inhabited an ever-expanding wonderland filled with increasingly absurd inventions, creatures and disasters. The series ultimately reached 169 storeys – 13 times 13 – before the pair decided it was the perfect place to stop.

The books went on to reach readers in 35 countries, with more than 13 million English-language copies sold around the world. One instalment became the fastest-selling book in Australian publishing history when it was released in 2016.

But Denton’s remarkable career stretched well beyond the Treehouse.

He wrote and illustrated more than 30 books of his own, including the Gasp! series, which was later adapted for television, and worked with some of Australia’s best-known children’s authors, including Mem Fox, Paul Jennings and Gillian Rubinstein.

His talent had been recognised decades before the Treehouse phenomenon. In 1986, Felix and Alexander won the Children’s Book Council of Australia’s Picture Book of the Year Award.

Yet perhaps Denton’s greatest achievement cannot be measured in awards or sales figures.

For countless children – particularly those who found traditional books intimidating or reading difficult – his drawings made opening a book feel like fun rather than work. Macmillan Children’s Books said a Treehouse book was often where a lifelong reading habit began, with Denton’s detailed illustrations rewarding children who returned to the pages again and again.

His family’s tribute captured the man behind all those drawings, and the enormous hole his passing leaves behind.

“Dad gave joy to millions of children around the world and after all those stories and all those lives he touched, he always came home to us,” they said.

“We are so grateful that his stories will continue to live on, bringing wonder, laughter and comfort to generations yet to come and most especially to his beloved grandchildren, who will grow up knowing him through the magic he left behind.”

Denton is survived by his wife Kristen, children Imogen, Eve and Max, and grandchildren Georgia, Lucy, Charlie, Alfie and Felix.

For the millions of children who disappeared into his drawings – and the parents and grandparents who watched them do it – Terry Denton leaves behind a particularly joyful kind of legacy.

The Treehouse may have stopped growing at 169 storeys, but the laughter inside it will be around for a very long time.