McMahon was known for portraying villain Doctor Doom in 2005’s Fantastic Four and 2007’s sequel, Fantastic Four: Rise of the Silver Surfer. He also played Christian Troy in Ryan Murphy’s Nip/Tuck and Cole Turner in Charmed. His more recent credits were in The Residence and The Surfer.

He played a half-human, half-demon in the WB supernatural series “Charmed” and a playboy plastic surgeon in the FX series “Nip/Tuck.”