Grivel was a ferret Sea Raider serving under Vizka Longtooth aboard the Bludgullet. He, along with the rats Feerog and Durgy, was rebellious against Vizka and they planned to have him killed. While discussing this in the mess, the weasel Snikey overheard them. Knowing Snikey to be Vizka's spy, Grivel had Durgy kill him. However, the deed did not go unnoticed; ship's cook Glurma spotted this and reported it to Vizka.
While looking for a leader for the shore party that was going to search for Redwall Abbey, Vizka Longtooth nominated Feerog, Durgy and Grivel for the job. When all three volunteered, Vizka "decided" that the three would fight to the death; last beast standing takes the job. Grivel was reluctant to fight his two messmates, and held his cutlass only half-heartedly. He was taken aback by Feerog, who accepted the challenge and ran the unlucky ferret through instantly.