"Halloween" is a Halloween-themed episode from the first season of the British animated children's television series Willo the Wisp. It first aired in the United Kingdom on BBC1 at 5:25pm on October 30, 1981.
The series takes place in a forest called Doyley Wood. It is home to the ghost-like title character (who usually only appears as a narrator), a plump fairy named Mavis Cruet, a Cockney caterpillar named Arthur, a cat named Carwash, a bird named Twit and a dog-like creature called the Moog, amongst other characters. The series' primary antagonist is a wicked witch named Evil Edna. Evil Edna takes the form of a television set with a "rabbit ears" antenna. Her antenna crackles when she casts a spell. She often threatens to turn the other characters into frogs and sometimes makes good on her threats. All characters were voiced by Kenneth Williams.
In the episode, it is revealed that Halloween is also Evil Edna's birthday. Mavis Cruet conjures up a present for the witch but Evil Edna plays a cruel trick on Mavis and her friends in return. Unfortunately for Edna, Mavis' magic only works as long as her friends keep thinking pleasant thoughts.
On the morning of Halloween, Mavis Cruet the fairy, Arthur the caterpillar, Carwash the cat, Twit the bird and the dog-like Moog decide to have a party that evening. Arthur is keen to carve a jack-o-lantern because it will give him the opportunity to eat some of the pumpkin. Mavis says that they can all wear masks.
Everything appears to be ready for the party but Mavis says that they have forgotten something. They have forgotten to invite Evil Edna. Arthur does not like the suggestion of inviting the television set witch at all, saying that she has never done anything except change them into frogs. However, Mavis says that it is not only Halloween but Evil Edna's birthday as well, meaning that she should not only be invited to the party but she should also be given a present. Reminding her friends that her magic only works as long as they all keep thinking nice thoughts, Mavis conjures up a "witch kit", consisting of a tall black hat and a flying broomstick. Mavis is pleased by how well the broomstick flies. Arthur says he would like to see the broomstick fly straight into Evil Edna's mouth. His unpleasant thought makes the "witch kit" vanish immediately and Mavis has to conjure up another one.
Shortly after the other characters put on their masks, Evil Edna arrives. She is delighted to get the "witch kit". She tells Mavis and her friends that she will never change them into frogs again because she will cast a spell which will make sure they stay exactly as they are forever.
After Edna flies away, the other characters find that they cannot take off their masks and realize that Edna's spell means they will be stuck on their faces forever. Arthur gets angry and begins to insult Evil Edna. His unpleasant thoughts put an end to Mavis' magic. First Edna's hat disappears and then her broomstick does too. Having lost her broomstick, Edna crashes to the ground. She breaks her antenna, her spell is broken and the masks vanish.