Fleaback was a male weasel slaver in the gang of Slagar the Cruel. He participated in Slagar's entertainment at Redwall Abbey by being a tumbler and helped drug the Abbey residents. He and Drynose sided with Threeclaws and ganged up on Halftail when the villains turned on one another. He was one of the five surviving weasels and was captured by Matthias and Orlando the Axe. Fleaback and the four weasels were later released and sent away southward.