Dubbed The Apprentice's Rottweiler, Claude Littner is famed for his outbursts, his nit-picking and his confrontational style of interviewing. He likes to terrify candidates on the TV show, and unsurprisingly, nothing scares Claude himself.
After being diagnosed with Non-Hodgkin Lymphoma and being told he had six months to live, Claude has come out stronger and even more fearless.
"I am very lucky to be alive, you know," the sharp businessman told The Mirror. "One day I had an argument with [Lord Alan Sugar], which is very rare.
"I adore my wonderful family and feared I'd never see my grandchildren grow up," said Claude Littner
"We were trading insults so I took a day off and popped to the doctor to check it out. But he said it wasn't a hernia and packed me straight off to see a specialist. I was told I had six months to live.
"It came as a huge shock, obviously. You think, 'Well, that's it'. You start the treatment and just feel powerless."
Claude, who is married to his "wonderful" wife Thelma with whom he has two sons, endured strong rounds of chemotherapy. For a period of time his health improved, but then the cancer returned and he was told he didn't have much hope.
The businessman has replaced Nick Hewer as Lord Sugar's aide
His specialist decided to try a pioneering stem-cell transplant, to help his body make new healthy blood. Fortunately, Claude's sister Tina was his perfect match.
"My sister saved my life. She doesn't stop reminding me of that – but she really did!" said Claude.
"I have been cancer-free since March 2000 and I'm so glad I'm alive. I adore my wonderful family and feared I'd never see my grandchildren grow up. It really does give you a whole new perspective on life."
Claude, who has a business school in West London named after him, has starred on The Apprentice since its launch. The 66-year-old has replaced Nick Hewer as Lord Sugar's aide for the 2015 series, which airs on Wednesday night at 9pm.