Willo the Wisp beech wood in Oxfordshire, near the director's home. 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. Other characters included Carwash, a snooty bespectacled cat
Willo the Wisp being shown on weekdays between the end of the main children's programming for that afternoon, and the BBC Evening news at 5:40pm. The series was repeated on satellite channel Galaxy in 1989 and on Channel 4 during the early 1990s. On the Kult Kidz Gold DVD there was an extra video "Do Not Touch" which featured the last part of "Cats and Dogs", where Evil Edna makes the screen blank. In January 2008, a promotional DVD containing all 26 episodes from Season 1 was distributed by "The Times" newspaper. A second series of 26 episodes (5 minutes each) was produced