(CNN) -- It's an itch he just hasn't been able to scratch. More than 54 years after he announced the success of Fidel Castro in the Cuban revolution, Larry King still hasn't been able to interview him.
Just two years ago, King was in Cuba to try to get that elusive Castro interview, but the Cuban leader remains the only major figure he hasn't interviewed, he said.
"Forget politics, he has run a country for 50 years, he's a successful revolutionary, an intriguing person," said King about why he remains fascinated.
One top interview he did secure -- with the late Venezuelan President Hugo Chavez in 2009 -- came back into focus recently with Chavez's death.
"What's funny is that he spoke perfect English off air, but once the interview started, we had an interpreter," King said. "He wanted to talk in his native language."
King -- the last person to interview Chavez on CNN -- recalls Chavez being easy to be around and engaging, even remembering him as a hugger and singer.
"He was a conflicted person. An enigma. Yes, he was against capitalism, but he helped a lot of people, especially in the Northeast (of the U.S.). When there was a shortage of oil, he gave a lot of free oil to that area."
Cala and King also talked about King's web-based show, "Larry King Now," that's been on Oratv.com and distributed by Hulu.com since July last year, and his backer -- Mexican billionaire Carlos Slim.
"Carlos Slim has become a good friend of mine," said King. "He invited me to Mexico to speak at an event about three years ago, and it turns out he had been watching me for years. Now, we work together."
"It's nice to have the richest man in the world be my partner," King added. "He's very good at standing aside and letting us do it." (According to Forbes magazine, Slim is the world's richest person with a net worth of $69 billion, having made his fortune in the telecommunications industry.)
Cala took the opportunity to tell King in person how much of an impression he'd left on him when he was a young man in Cuba 15 years ago.
"When I first saw you, I was in Cuba and not knowing what my future would be," Cala said. "And, now, I'm sitting here and interviewing you. So, dreams come true."
Cala even paid homage to his hero in his wardrobe choice for the interview, greeting King wearing a matching button-down shirt, tie and signature black suspenders.
Since King lived in Miami for 20 years, some might find it odd that he never learned Spanish.
"I don't have a linguistic ear. I never picked it up," King said. But he said he still loves the language and music. "I've always had Latin flavor."
The interview was done in English and will be dubbed into Spanish for the CNN en Español show to air on Monday, March 25, at 9 p.m. ET.