S5, E15: Samantha and Darrin ask Cousin Serena, a witch who barges in at awkward moments, to stay away from a dinner for the Tates and a client, Clio Vanita. Clio plays up to Darrin, tossing off Italian phrases, and putting Samantha down. She rejects Darrin's advertising slogan, but continues to pursue him. When Darrin fends her off, Clio threatens to take her account over to another agency, but still tries to lure him to Rome. Serena, invisible, feels Clio is trying to make a monkey out of Samantha and decides to turn Clio into a monkey instead. Still affectionate, Clio clings to Darrin. Samantha refuses to have the animal in their bedroom. Darrin is horrified to learn the monkey is Clio. He orders Serena to change her back and leave the house. Serena leaves, but Clio is still a monkey. Darrin worries about the consequences if Clio doesn't show up for a meeting at the office. Samantha takes the chattering monkey to the patio for the night, muttering a few choice Italian phrases of her own.