Photo by Paul Archuleta/FilmMagic Actress Billie Hayes attends the "H.R. Pufnstuf" American Cinematheque special screening and Q&A at Aero Theatre on November 20, 2010 in Santa Monica, California. Billie Hayes, who played the cackling Wilhelmina W. Witchiepoo on Sid and Marty Krofft's H.R. Pufnstuf and the scrappy Mammy Yokum in the Broadway and big-screen versions of Li'l Abner, has died. She was 96. Hayes died Thursday of natural causes at Cedars-Sinai Medical Center in Los Angeles, a family spokesperson said. After starring as the evil protagonist on the 1969-70 kids program H.R. Pufnstuf, she reteamed with the Krofft brothers in 1971-72 on