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 who was based on Noël Coward with the catchphrase "My eyes are not first-class, you know"; The Moog, a supposed dog who is not allowed to think for himself; Twit, a small bird; The Beast, a former human prince turned into a hairy shambling creature by Evil Edna; the Astrognats, a group of bugs who explore outer space by means of their toadstool rocket; the Bookworm; gnomes; and a regiment of toy soldiers.

This continued a tradition of short cartoons, such as The Magic Roundabout and The Wombles, being shown on weekdays between the end of the main children's programming for that afternoon and the BBC Early Evening news at 5:40pm.

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 August 2024 the new DVD and Blu-ray versions both contained a special feature on the first series disc: the full 1975 original appearance of Willo the Wisp in the award-winning Super Natural Gas animation.