20. Estelle Harris as Estelle Costanza on Seinfeld

Most of the mothers on this list are overbearing, but none are as batty as Estelle (Estelle Harris), the drama queen who, together with her equally nuts husband, made George (Jason Alexander) the awkward, socially stunted man he is today. Even in his adulthood, mommy can shame him into submission, no example more memorable than when she threw out her back after catching George choking the chicken in a garage.