Hayes endeared herself to a generation of young TV viewers playing Wilhelmina W. Witchiepoo on the short-lived 1969 Sid and Marty Krofft NBC children's series. "With a performance panache that was over-the-top even by the wacky standards of the Sid and Marty Krofft universe of costumed creatures, Hayes was an immediate scene-stealer," says Greg Evans. "Series-stealer, actually: Though Witchiepoo was the H.R. Pufnstuf villain, intent on stealing the magical, talking Freddy the Flute as if he were a pair of ruby slippers, Hayes’ wildly entertaining vaudeville, slapstick style had legions of young viewers rooting her on to a victory that never came. 'Why me?,' she’d whine or sob after the inevitable backfiring of her latest evil scheme."