Bewitched - Season 3 - Eps 4: Accidental Twins
Samantha is babysitting little Jonathan Tate, and Aunt Clara turns him into a set of twins. Now how are we going to explain this to the Tates? While Aunt Clara tries to remember the spell, Samantha does everything to keep Larry and Louise from knowing that they have an extra son.
About Bewitched

Title: Bewitched
First Air Date: 1964-09-17
Last Air Date: 1972-03-25
Status: Ended
Rating: 7.861/10 (from 695 votes)
Language: EN
Seasons: 8
Total Episodes: 254
Network: ABC
Genres: Sci-Fi & Fantasy, Comedy, Family, Drama
Production Companies: Columbia Pictures Television, Screen Gems
Synopsis
Samantha Stephens is a seemingly normal suburban housewife who also happens to be a genuine witch, with all the requisite magical powers. Her husband Darrin insists that Samantha keep her witchcraft under wraps, but situations invariably require her to indulge her powers while keeping her bothersome mother Endora at bay.
Cast

Elizabeth Montgomery
Samantha Stephens

Dick Sargent
Darrin Stephens

Agnes Moorehead
Endora

David White
Larry Tate