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.