The Rattling Girl of Lawndale is the name given, by Lawndale High students, to a female student of urban legend status.
According to legend, the Rattling Girl was a popular teenage girl from the 1960s that was considered almost perfect. Desiring to achieve perfection, she thinks her eyelids are too fat, and therefore increased the intensity of her diet just before a school dance.
This results in a extremely thin body and a seemingly perfect figure (according to her colleagues). However, a side effect was that her bones would rattle with every movement she made. When this is noticed at a school dance, she is laughed out of the school.
Furious, she would take her revenge on the female students, haunting their sleep with a rattling sound. Legend had it that the eyelids of the sleeping students would be eaten. This would result in their fear of sleep and therefore their perpetually sleep-deprived appearance, which then resulted in popular girls becoming unpopular.
This character makes her only appearance during the episode "Legends of the Mall", when her story is told in flashback by Stacy to Quinn, when the Fashion Club is left stranded in a seemingly bad part of Lawndale. In the telling (i.e. Quinn's imagination), the character bears the same appearance as Sandi Griffin, which is ironic as Sandi dismisses the whole legend, claiming that "...everyone knows that story was just made up by unpopular people to try to scare popular people into becoming unpopular." Then the slightest noises causes them to run in terror.