By Helen Briggs
Health reporter, BBC News
As the costumed superhero known as the Green Cross Man, he told the children of the 70s to Stop, Look and Listen.
Now, the British actor best known as Darth Vader in the original Star Wars films has become the unlikely hero of a very different campaign.
Diagnosed with prostate cancer at the start of the year, Dave Prowse MBE has found himself raising awareness of men's health.
"There's this terrible embarrassment," says the former bodybuilder and weightlifter.
Darth Vader's been very very good to me
"You've got to get over to men that there is no embarrassment in going to the doctor and letting the doctor probe around and having a look to see how you are.
"It doesn't worry me in the slightest and it shouldn't worry any man."
The 72-year-old, who is married with three children, only discovered he had prostate cancer through his charity work. At a golf tournament in aid of the Prostate Cancer Charity, he was asked to present the cheque to a representative.
She happened to ask if he had had a PSA test, which is recommended in all men over 50.
"The lady said: 'Thank you very much, and by the way, have you ever been tested for prostate cancer yourself?'" he recalls.
"I said: 'No, I'm perfectly all right thank you very much, and I'm not having any problems on that side of things.'"
As the Green Cross man in the 1970s
But the conversation lingered in his mind, and when he visited his GP a few months later for an unrelated matter, he asked for the blood test.
A biopsy revealed suspicious signs, and he was diagnosed with prostate cancer. He was treated with radiotherapy and medication, and says the only after-effect was an occasional "hot flush".
Because the disease was caught early, the future now looks good.
Prostate cancer is the most common male cancer in the UK, accounting for almost a quarter of male cancers
Each year, nearly 35,000 men are diagnosed and more than 10,000 die from the disease
Most men with early prostate cancer are diagnosed because they have problems with bladder habits
"As far as I'm concerned, I've been given the all clear," he explains. "We had a letter from the surgeon saying as far as the future was concerned the prognosis was excellent. That basically is it."
He is now keen to carry on travelling the world to appear at Star Wars conventions.
"Darth Vader's obviously been very very good to me," he says. "I did the first three movies - Star Wars, Empire (Strikes Back) and (Return of the) Jedi, which took me from '76 to '82.
"But the interesting thing of course is that since Star Wars came out, a whole culture has expanded worldwide in what I call the fandom business.
"And wherever you go, people turn up literally in their thousands."