Jim Carrey endured a highly challenging transformation to play the Grinch in the 2000 film 'How the Grinch Stole Christmas,' directed by Ron Howard. The actor worked with a CIA-trained specialist to cope with the physical and mental toll of the role. The process involved three to eight hours of makeup daily, including prosthetics, fake teeth, contact lenses, and an itchy yak hair costume, which caused significant discomfort. Carrey described the suit as 'not too fun,' with limited movement due to prosthetic fingers and restricted vision from contact lenses. Despite requesting this extreme transformation, he was unprepared for the intense pain and discomfort, which led to panic attacks and near quitting the film. Howard observed Carrey lying on the floor between takes, visibly miserable. To keep him motivated, producer Brian Grazer brought in Richard Marcinko, a former Navy SEAL and CIA survival trainer, who provided techniques to manage pain and mental stress, such as punching himself, eating excessively, and listening to joyful music like the Bee Gees. Carrey credited the Bee Gees' music with helping him endure the makeup process, which was eventually reduced to about three hours. The actor also trained with Marcinko to develop mental resilience, using methods like self-punching and other survival tactics. Despite the hardships, Carrey found performing in the costume to be transformative and rewarding. The film remains accessible for viewing on streaming platforms like Peacock and Amazon Prime Video.