Dr Graeme "Spluttergrunt" Stevenson walks around with dung beetles glued to his hat, waxes lyrical about earthworms and may start singing at any moment.
It's no surprise that the passionate and effervescent "poo-ologist" has been winning the hearts of Tasmanians for well over 30 years.
And it's certainly no surprise he was named Tasmania's Senior Australian of the Year for 2020 for his work in promoting healthy soil.
"I'm a show-off, there's no two ways about it," he said.
"What a life I've had! And I've loved every minute of it."
His long list of achievements include introducing five species of dung beetle to Tasmania, helping fix soil slips and slumps along Tasmania's coastline, managing about $1.5 million worth of Landcare projects and writing various books and articles.
But Dr Stevenson still thinks most fondly of the hundreds of young hearts he won over during his years of volunteer work in schools.
"One time I brought in a plate of poo, they never forgot what I taught them," he laughed.
"Poo should be in the ground, not on the grass where the animals eat!
"I invented Dr Spluttergrunt to make it fun. I'd wear a coat and a stethoscope and bring in 'Sally the Sick Soil'. It was usually something I'd dug up beforehand.
"I discovered I was an actor. And those kids, oh they loved it. And I loved them."
Well into his seventies, the Landcare activist is as warm and excited about the natural world as ever.
"I don't know what drives me," he said.
"No one has ever asked me. I just love it."
He said he'd been "tickled pink" to learn he'd been nominated for the Tas Australian of the Year awards last year.
"I didn't know who nominated me," he said.
"I got to meet Wendy and Ken Gourlay on the night, it was wonderful.
"But no one asked me for a biography ... I have my suspicion but I can't prove it - Pip Courtney from Landline had all my info."
Dr Stevenson said he had been thrilled to show up to Government House and find that he had been named for an award alongside a marine research scientist, a social justice advocate and a men's health advocate.
"What a gorgeous team, and I don't mean their looks!" he said, flashing a photograph from the awards night he keeps at hand.
"They're only young and doing marvellous things.
"It's a wonderful thing to nominate someone, I'm not sure who I'll nominate this year ... there's plenty out there."