Karvil was the steersrat onboard the Sprayraider under captain Sculrag. When their craft ran ashore, the majority of the crew was shot dead by the vengeful otter Grath Longfletch. Behind the hull of their wrecked ship, the two remaining rats hid and attempted to wriggle out of their situation. They got into a fight and Sculrag kicked Karvil's knife out into the open. Karvil attempted to retrieve it but was shot between the eyes by Grath.