Sister Sage was a plump, older female mouse, and a Sister and resident of Redwall Abbey. She said that she once was a "snip of a mouse" when she was younger, and that Brother Hubert was once in love with her. She fell "out of love with Hubert and into love with food", instead.
When she made food for a feast, she tended to snack on whatever she was making. She often chatted with Mother Mellus as she prepared salads and such for Abbot Bernard's Golden Jubilee.