Myrtle was a female mouse and the loving sister of Matthias. She appeared in Episode 1 of the Redwall TV Series, Cluny the Scourge part 1. She didn't appear in the book Redwall, or any other novel, and was created by Nelvana.

Myrtle rescued her brother Matthias from their burning home, after Cluny the Scourge attacked their village and left a young Matthias to perish in the flames. She wandered with him on her back through winter to Redwall Abbey. They were found by Constance and Abbot Mortimer and brought inside. Later, Myrtle died from fatigue.

Not to be confused with Myrtle.