Mr. Benn (1971)

S1E4 The Wizard

After enjoying a magic show in the park, Mr. Benn decides to visit a costume shop. He puts on a wizard's cape and pointed hat, and when he steps through the changing room door, he finds himself in a wizard's cave. There, he encounters two men who invite him to the Palace to meet their king and queen. Once at the royal court of the joyful kingdom, the queen expresses her belief that her husband—a short, easygoing, cheerful man—lacks the qualities of a true king. She asks Mr. Benn to use his wizardly abilities to change him, but each attempt fails to meet the queen's expectations.