It Shouldn't Happen to a Dog

S1 E3: Samantha gives a dinner party to impress Rex Barker, one of Darrin's clients. Rex brings along his date, Babs Livingston, but advances on Samantha in the garden when he gets drunk. Barker becomes too aggressive and Samantha changes him into a dog. Darrin, thinking only of the possible loss of the account, is furious and Samantha locks him and the dog out. Endora sets a cat on the dog, who comes out much the worse for wear. Samantha takes Barker to a vet and then changes him back to a man. The next morning, Barker, not having learned a thing from the night before, again makes a pass at Samantha. This time Darrin floors him with a punch and walks out on his job. Later, Barker apologizes and signs the contract on condition that Darrin return to the agency.