Surreal works from the home of François-Xavier Lalanne and his wife Claude expected to fetch up to £20m

For years, a giant brass and Sèvres porcelain grasshopper that could, if needed, double as a wine-cooler sat outside the royal apartments at Windsor Castle; a gift from French president Georges Pompidou to the Duke of Edinburgh during a state visit to France in 1972.

Across the Channel, an hour from Paris, the home of its late creator François-Xavier Lalanne and his artist wife Claude is full of such wonderful and whimsical creatures: a huge rhinoceros that transforms into a desk; a bronze cabbage on chicken legs; a herd of sheep that can be sat on, tables of enormous ginkgo leaves.

François-Xavier died in 2008; now, after the death earlier this year of Claude, whose jewellery creations inspired designers including Yves Saint Laurent, Hubert de Givenchy, Karl Lagerfeld and Stella McCartney, more than 280 items from the couple’s private collection will be auctioned by Sotheby’s in Paris on 23-24 October.

The sale will excite international collectors, whose devotion to Lalanne works have sent prices soaring in recent years. Among items for sale are François-Xavier’s famous sheep in epoxy and wool, an elephant side table, monkey lamps and a 6ft rabbit in patinated bronze. The auctioneers will not give individual price estimates for the lots.

Les Lalanne, as they were known, lived and worked at a rambling property at Ury, near Fontainebleau, creating their surreal parallel universe of functional fauna and flora. French president Emmanuel Macron described it as a mix of the “dreamlike madness of fairytales and the sublime disorder of nature”.

Florent Jeanniard, the Sotheby’s expert cataloguing the sale, says it is the first time the couple’s personal collection has come up for auction. “These are not just works seen in galleries and exhibitions but pieces that were in their home and part of their daily lives,” Jeanniard told the Observer. “As they lived with these objects, I think we can safely say they were, of all their works, the ones they preferred.”

The lots – 200 of them by Les Lalanne – are expected to fetch up to €22m (£19.7m). Pre-auction public exhibitions will be held from 3-6 October in New York, Hong Kong, London and Paris.

Facebook Twitter Pinterest The giant brass and porcelain grasshopper given to the Duke of Edinburgh in 1972. Photograph: Royal Collection Trust

Les Lalanne met in 1952 at a gallery show of François-Xavier’s paintings. At the time, he rented a studio flat next to the Romanian-born sculptor Constantin Brâncuși, who would visit with bottles of vodka and cartons of Sobranie cigarettes, and who introduced him to Max Ernst, Man Ray and Marcel Duchamp.

After the couple moved in together, François-Xavier swapped painting for sculpture. It was the start of a partnership that lasted more than half a century, though they created separately and collaborated on only a handful of works.

He produced large animals with hidden compartments – among them a giant bird that opened to reveal a bed and a hippopotamus with a bath inside – blurring the distinction between sculpture and the decorative arts. She combined creatures with flowers, leaves and plants, most famously in Man with a Cabbage Head, which singer-songwriter Serge Gainsbourg featured on an album cover in 1976, and intricate jewellery using electroplating – coating organic matter with copper by the means of electricity.

Their first joint exhibition in 1964 was a disappointment. Abstract art was à la mode, with an emphasis on the aesthetic not functional. Critics were not impressed. “Those who criticised our work said it was ‘grotesque’ because they felt sculpture should not serve any other purpose that to be looked at. The idea of sculptures that had a use was a complete nonsense,” Claude said afterwards.

Facebook Twitter Pinterest François-Xavier Lalanne and his wife Claude Photograph: WestImage - Art Digital Studio/©JP Lalanne/courtesy Sotheby’s

Popular acclaim eluded them but the couple gained a following among collectors, celebrities and fellow artists, including Magritte and Picasso.

In 1966, François-Xavier sent a “herd” of 24 bronze and wool sheep that would soon become his trademark to the Salon de la Jeune Peinture in Paris. They attracted the attention of art collectors and celebrities, including Saint-Laurent and his partner Pierre Bergé. YSL commissioned a series of 15 intricate Claude Lalanne mirrors for his studio and asked her to make moulds of the body of his model and muse Veruschka – born Countess Vera von Lehndorff – that were used in his 1969 autumn/winter collection.

At Ury, the farmhouse, studios and garden are packed with Lalanne creations. Visitors are confronted by a huge rabbit with windblown ears, hooves for feet and a bird tail. A bronze cat with an elongated body and what appears to be a fishtail, opens to become a bar. There are cabbages on legs, and sheep sculptures graze in the courtyard.

Today, a Lalanne work can reach up to 10 times its catalogue estimate at auction. (The Windsor Castle grasshopper has been moved due to renovations, but a spokesperson said it was still part of the duke’s “private collection”.)

“There was always a small circle, an exclusive circle, including Saint-Laurent, Bergé, the Rothschilds, people who knew about art as well as collectors interested in their work, even if they weren’t known to the wider public,” Jeanniard said.

This latest auction has raised eyebrows in France, where there are mutterings about the couple’s private collection being sold instead of being transformed into a museum or art foundation. Jeanniard dismissed the criticism. He said the Lalannes’ four daughters had been forced to sell the works to pay death duties.

“To my knowledge, nobody from the French state has approached them with another solution, so they have no choice. That’s the system in France,” he said. “Besides, instead of being proud and saying how wonderful that these French artists are getting worldwide recognition, there is criticism. It’s very Paris, very French.”

He added: “These works are extremely poetic, surreal and more and more universal. Like Egyptian or Greek art, they are a continuation of a certain classicism. It’s art that is universal and speaks to the whole world.”

As he toured the Ury house and studios, Jeanniard was asked what was his favourite Lalanne creation. “All of it,” he said, without hesitation. “The whole collection.”