From the Super Mario Wiki
“I made a picture called Super Mario Bros., and my six-year-old son at the time — he’s now 18 — he said, 'Dad, I think you’re probably a pretty good actor, but why did you play that terrible guy King Koopa in Super Mario Bros.?' and I said, 'Well Henry, I did that so you could have shoes,' and he said, 'Dad, I don’t need shoes that badly.”
Dennis Hopper (May 17, 1936 – May 29, 2010) was an American actor who portrayed President Koopa in the live-action Super Mario Bros. film, which was released in 1993. Since his immortalized role as Frank Booth in the Oscar-nominated "Blue Velvet," he made a steady career of playing villains. He has acted as the antagonist in a number of other films in addition to his role as the Koopa King. He died on May 29, 2010 at the age of 74. A few months later in August, the Super Mario Bros. film was released on DVD in commemoration of him.