According to rumor, after the studio fired original director Richard Stanley, he convinced the makeup crew to turn him into one of the background mutants, so he could keep tabs on the making of his dream project. He supposedly did not unmask himself until the wrap party. In his autobiography, Val Kilmer mentioned Stanley would yell at him between takes in dog-man make-up, and Kilmer could recognize his voice but not place him among the many extras.
Marlon Brando wore a small radio receiver to help him remember his lines. Co-star David Thewlis claimed "He'd be in the middle of a scene and suddenly he'd be picking up police messages and Marlon would repeat, 'There's a robbery at Woolworths'."
When Val Kilmer encountered Richard Stanley during the wrap party, he apologised for costing the director his job. Marlon Brando later offered to compensate Stanley. To his regret, he didn't take it.
David Thewlis has stated that he would like to give a real account of the film's production, but fears that if he did he would never work again.