Rabbi Hyman Krustofski

The Simpsons includes a large array of supporting characters: co-workers, teachers, family friends, extended relatives, townspeople, local celebrities, fictional characters within the show, and even animals. The writers originally intended many of these characters as one-time jokes or for fulfilling needed functions in the town. A number of them have gained expanded roles and have subsequently starred in their own episodes. According to the creator of The Simpsons, Matt Groening, the show adopted the concept of a large supporting cast from the Canadian sketch comedy show Second City Television.

Agnes Skinner (voiced by Tress MacNeille) is the mother of Principal Skinner and first appeared in the first season episode "The Crepes of Wrath" as an old woman who embarrassingly calls her son "Spanky". However, as episodes progressed, the character turned bitter. She is very controlling of her son and often treats him as if he is a child. She hates Edna Krabappel due to her son's feelings for the other woman. Agnes has married four times. Several Springfield residents (including the Simpsons) are afraid of her. When "the real Seymour Skinner" arrives in Springfield, Agnes ends up rejecting him in part because he stands up to her, but also because unlike Skinner/Tamzarian, her biological son is independent and doesn't need her anymore, while Skinner immediately reverts to a good-for-nothing without her.

Agnes' first name was revealed in the seventh season episode "Bart the Fink". Before that, the character was known as "Mrs. Skinner". In the beginning of the series, the writers made several references to Agnes and Seymour's unhealthily close relationship as similar to that of Norman Bates and his mother. In "Boy Meets Curl", it is revealed that Agnes' resentment towards Seymour may have begun even before her son was born — during the 1952 Summer Olympics in Helsinki, Agnes competed in the pole vaulting event while 9-months pregnant. When Seymour makes his first kick, he hits the bar, thus, making Agnes lose and subsequently crushing her dreams. However, this would contradict the earlier episode when it is revealed that Seymour is not her birth son. In "Grade School Confidential", it is revealed that Agnes enjoys collecting pictures of cakes that she cuts out of magazines, a hobby she began in 1941. She does not like to eat them, however. In the twenty sixth season episode "Sky Police" she mentions that she has a brother Stevie.

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