Gerna was a small male rat Sea Raider serving aboard the Bludgullet under Vizka Longtooth. He was sent with fellow rat Firty to search for a good place to dig into Redwall Abbey, but encountered Tantail and Dirril, two of Gruntan Kurdly's Brownrats, instead. The rats pursued the Sea Raiders hotly. Gerna was a very minor character, nothing else is known. It is presumed that he died during the Battle of the Plateau.