Swiffo was a male sea otter. He was Skor Axehound's youngest son and the brother of Ruggan Axehound. He was of more of a peaceful nature than the rest of the Rogue Crew sea otters, and joined up with the Fortunate Freepaws as a scout.
He led Posybud, Uggo Wiltud, and the Freepaws through a marshland to escape Razzid Wearat and the crew of the Greenshroud, and convinced Sircolo to aid them in their journey. When Uggo and Posy left the Freepaws to go with the Guosim to Redwall Abbey and fight Razzid, Swiffo went with them, his reckless sea otter nature finally getting the better of him.
Swiffo was a very good climber for an otter; he discovered Hiposir and his tribe of bats in an overhead tunnel. Later, he raced Log-a-Log Dandy Clogs up a tree, but was shot by a poisoned dart from Ketral Vane, which killed him. His death was greatly mourned by his family; after his brother avenged him, he was buried at Redwall Abbey, and sung to rest by Lancejack Sage.