Alice Cooper's career spans more than four decades. He's a singer, songwriter and actor. He's appeared in such movies as "Wayne's World" and "Dark Shadows," but being on "The Muppet Show," he says, has been one of his favorite guest appearances. Cooper tells Yahoo Entertainment he got a call to be on the Halloween show in 1978 but was concerned "The Muppet Show" would "water down" his image. After some thought he decided to do it and says it was the most fun he's had. "It was the number one show in the world," Copper explains. "Everybody in the world loved that show and it was cleverly written." He rehearsed in London for a week and connected so much with the muppets he felt they were human. "They would react exactly how a person would react," he explains. "They never broke character." Watch the video above for more with Alice Cooper.