Sister Serena was a shortsighted, rotund, female mouse Infirmary Keeper at Redwall Abbey. She assisted in the healing of Hon Rosie along with Simeon, Sister Sage, Abbot Bernard, and Mellus. Sister Serena also took care of Dibbuns and protected them during Greypatch's siege of the Abbey. Sister Serena was one of the creatures who helped make the Tapestry of Martin the Warrior.