Marin admitted that he was approached to join the cast of the Super Mario Bros. movie as the titular character alongside John Leguizamo’s Luigi, but he luckily turned it down.
Marin mentioned that he turned it down and that they also offered him royalties on the Super Mario Bros. movie.
Marin definitely made the correct decision not to join the cast of the Super Mario Bros. movie, royalties or not.
You can read more about Cheech turning down Super Mario Bros. over at Frobes.