The Yoshi puppet was capable of making 64 separate movements due to 200 feet of cable crammed inside its 3 foot tall structure. In all, no less than 9 puppeteers were used to operate the Yoshi puppet.
Explaining why he did the film, Dennis Hopper said "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.'" See: Henry Hopper.
Bob Hoskins didn't know that the film he was making was based on a game until his son asked him what he was working on. When Hoskins mentioned the film's title, his son immediately recognized it and showed Hoskins the game on his own Nintendo Entertainment System.
In a 2011 interview with The Guardian, Bob Hoskins described the film's production - "It was a f*ckin' nightmare. The whole experience was a nightmare. It had a husband-and-wife team (Rocky Morton and Annabel Jankel) directing, whose arrogance had been mistaken for talent. After so many weeks their own agent told them to get off the set! F*ckin' nightmare. F*ckin' idiots."
In his 2007 autobiography, John Leguizamo states he and Bob Hoskins hated working on the film and would frequently get drunk to make it through the experience. Both men apparently knew the movie would turn out bad, so they simply tried to make the best of it. He also stated he felt one of the biggest reasons the movie turned out the way it did was because the directors wanted a more "adult" movie while the studio, considering the source material, was looking for a children's film.