Tassy was a female squirrel resident of Redwall Abbey. She was one of two young Dibbuns who were captured during the time of Vilaya, the Sable Quean. She and her mole friend Guffy wandered out of the open wallgates of Redwall and were bound, gagged, and carried away by Ravagers. She was imprisoned with the rest of the babes at Althier.
When Axtel Sturnclaw gained entrance to Althier, he rescued Tassy as well as Borti. It was Tassy who bound his foot wound, proclaiming that she wanted to be an Infirmary keeper when she was older. Axtel took them home. Tassy is a somewhat minor character, so what happened after her return to the Abbey is unknown.