The Munsters - Season 1 - Eps 10: Autumn Croakus
Grandpa is feeling lonely and depressed so he contacts a matrimonial agency to find a mate. The agency sends over a nice looking elderly woman who find Grandpa to be delightful. She turns out to be the Black Widow: she makes her living by marrying her suitors, getting them to sign a life insurance policy naming her as beneficiary, and then murdering them.
About The Munsters

Title: The Munsters
First Air Date: 1964-09-24
Last Air Date: 1966-05-12
Status: Ended
Rating: 8/10 (from 428 votes)
Language: EN
Seasons: 3
Total Episodes: 70
Network: CBS
Genres: Comedy, Sci-Fi & Fantasy, Family
Production Companies: Universal Television, Kayro-Vue Productions, Universal Television Entertainment
Synopsis
A family of friendly monsters that have misadventures all while never quite understanding why people react to them so strangely.
Cast

Fred Gwynne
Herman Munster

Yvonne De Carlo
Lily Munster

Butch Patrick
Eddie Munster

Al Lewis
Grandpa

Pat Priest
Marilyn Munster