kenneth williams provided voices for all of the characters. the principal narrator, willo the wisp, was a blue, floating creature drawn as a caricature of him, while the name refers to the ghostly light will-o'-the-wisp from folklore. the other main characters were arthur the caterpillar (as a gruff cockney), mavis cruet, a plump, clumsy fairy with an erratic, magic wand, and the principal antagonist, evil edna, a witch in the form of a walking, talking television set who could zap people with her aerials.