For the second installment, Tom Six wanted to cast "a fat, small, chubby guy" as the imitation doctor to offset the skinny Dr. Heiter. When Laurence R. Harvey (who eventually got the part of Martin) came into casting, Six wanted to see how far he was willing to go. "I asked him, 'Are you willing to rape a chair? Can you rape the centipede?'" he says. "Then Laurence grabbed the chair and made love to the chair and I thought, This is my guy."