Sister Snowdrop was an old female mouse of Redwall Abbey. She was the assistant to Old Quelt, which made her a Recorder and a Librarian. She had a white patch of fur on her head, which is why she is so named. She also wore square-shaped spectacles and helped to solve the riddles of Sister Geminya. After Old Quelt retired, Sister Snowdrop became his successor as Librarian of Redwall, whereas the squirrel Girry became Recorder.