Prudy, a devout Roman Catholic, is very cruel towards her daughter with whom she has a love/hate relationship. She is racist and considers Tracy Turnblad and her views on race relations a bad influence on Penny.
In the 2007 film, she detains Tracy in the basement of the Pingleton house, which doubles as a bunker in case of a Soviet invasion. This shows that she may also be very paranoid, also with it being during the Cold War. Penny seems very familiar with the idea of being tied up by "the jump rope", which shows that Prudy has been abusive on more than one occasion.
She mentions her husband as serving time in prison, and implies that he is physically violent towards Penny. As she watches The Corny Collins Show, she sees Seaweed and Penny kiss at the Miss Hairspray Pageant, causing her to fall over her coffee table in horror. She then begins to clean the TV in hopes that something on the TV is making Seaweed's skin darker and not whiter.
In the 1988 film she was played by Joann Havrilla while in the 2007 remake, she was played by Alison Janey.