Skywhale, believed to be the first hot-air balloon commissioned to celebrate a city's 100th birthday, has the flowing form of a giant pink-and-black-hued fish.
But its face could be that of a parrot, or a turtle, and the renowned artist who designed it, Patricia Piccinini, refuses to say just what it is.
Piccinini, whose work has been shown at the Venice Biennale and London's Victoria and Albert Museum and who recently exhibited works in the US, Turkey and London, said Skywhale was a piece about "wonder and nature".
"It's meant to inspire a sense of wonder in 'what is it?'" she told the ABC of the towering sculpture which used more than 3.5 kilometres (2.2 miles) of fabric and took 16 people some seven months to make.
At 34 metres long and 23 metres high, the Skywhale is at least twice as big as a standard hot-air balloon and weighs half a tonne.
The balloon, which was made in Bristol in the United Kingdom and cost Aus$172,000 (US$173,000) has sparked outpourings on social media, with some describing it as a waste of money while others enjoyed the sense of fun.
On the Daily Telegraph website, Tim Blair said it was the perfect symbol for the city which is home to the national parliament -- "a bloated, gaseous, multi-breasted monster feeding those who dwell in its poisonous shadow while leeching off the rest of us".
"I've seen more attractive road kill than the grotesque #skywhale," was once response on Twitter.
But the odd-looking balloon also drew support despite the fact that whales are never seen in Canberra, a landlocked city between Sydney and Melbourne.
"The naysayers will have a go at #skywhale with knee-jerk reactions about wasting public money. I think it's an imaginative & inspiring work," wrote one supporter on Twitter.
The Skywhale will be officially unveiled outside the National Gallery of Australia on Saturday as part of an international sculpture symposium, before making its first flight over Canberra on Monday.
The balloon, which has been designed to carry a pilot plus two passengers to an altitude of 3,000 feet, will be seen at the Museum of Old and New Art (MONA) in Hobart and the Australian Centre for Contemporary Art in Melbourne later this year.
Voice of Russia, AFP