Rhonda is a character from Trick 'r Treat, a 2007 Halloween horror anthology film.
Macy, Schrader, Chip and Sara are going trick-or-treating, collecting jack o' lanterns. When they stop at the house of their classmate Rhonda, they invite and lure her to the quarry. When they arrive, Macy said it was the site of the urban legend The Halloween School Bus Massacre.
30 years ago, the bus had eight mentally challenged kids dressed in masks and Halloween costumes chained to their seats as Mr. Kreeg (Brian Cox) was paid by their parents to kill their children. A kid in the vampire costume broke free and tried to drive the school bus to safety but accidentally drove it into the lake. Mr. Kreeg survived and the kids did not. The eight jack o' lanterns are meant as the offering to eight kids who died.
They take an elevator to the bottom of the quarry, but Chip and Rhonda are attacked by ghoulish figures. This is revealed to be a cruel prank to scare Rhonda all along, when Macy kicks a jack o' lantern into the lake, the eight zombie children came back from the dead. The teens beg Rhonda to let them in the elevator, but she refuses and goes alone with the jack o' lantern instead as the teens get brutally slaughtered in cold blood by the ghoulish children.