He was Sir Peter Scott - and today we celebrate the centenary of his birth.
It's hard to imagine a life better spent. Not only was he passionate about nature and conservation, he was also deeply concerned about the planet's ability to withstand human demands on its resources - an issue now known as sustainable development.
Another of his driving interests was preserving the Antarctic wilderness from human exploitation.
Hardly surprising, perhaps, when you consider his father was the legendary Robert Falcon Scott - Scott of the Antarctic.
It was in 1961 that WWF was founded by Sir Peter and other eminent people of the time. He was crucial to the whole development of WWF," his friend the Duke of Edinburgh, President Emeritus of WWF, recalled. "I think his great contribution was that he was a brilliant communicator.
"For example, his television programmes in the 1950s and '60s were in those years as popular, as convincing, as David Attenborough's are now."
Sir David himself knew Peter Scott well and remembers him with great affection. "He was a supreme communicator, but he also knew about animals and their habitats. Today, his lasting legacy is the world conservation movement, and we owe him a great debt."
As well as WWF, Sir Peter Scott also founded the Wildfowl & Wetlands Trust and remained honorary director for the rest of his life. In 1982 he originated the International Union for Conservation of Nature Red Data Books, the vital reference resource which defines the status of the world's endangered species. He also founded many local and regional conservation bodies from rural Gloucestershire to the Falkland Islands.
For all his extraordinary achievements, Sir Peter Scott was appointed a Fellow of the Royal Society and created a Companion of Honour by the Queen in 1987. He died two years later at the age of 79.
He was, quite simply, the most influential conservationist of the 20th century - and his legacy lives on, not least through WWF's numerous worldwide programmes.
Of WWF, Sir Peter himself said: "We shan't save all we should like to - but we shall save a great deal more than if we had never tried."
One of Sir Peter's most visible legacies is WWF's panda logo, which he originally designed back in 1961.
He wanted a simple black and white image that would be instantly recognisable and could be copied easily. The choice of a species that was perilously close to extinction imbued his iconic design with a powerful message - that there was an urgent need to safeguard the natural world.
That need is of course greater than ever today, with so many wide-ranging threats and challenges to our environment - not least from climate change.
And Sir Peter's design heritage continues to have a powerful impact through WWF's unique Pandamonium project. Leading British artists and designers have created new works of art - using Sir Peter's iconic panda - that help to highlight the work of the organisation he co-founded almost 50 years ago.