Sergeant Gruff is a sergeant of the Guard Dogs who protect the Castle of the Crown. He is most often found guarding the doors to the Castle with Woof. When Alexander first arrived on the Isle of the Crown, it was the sergeant who demanded proof of the prince's identity. After viewing Alexander's Royal Insignia Ring, Sergeant Gruff announced the prince to Captain Saladin. After Alexander's audience with Abdul Alhazred, Gruff followed Saladin's orders and refused to allow Alexander back into the castle.
Sergeant Gruff is a character from King's Quest VI: Heir Today Gone Tomorrow.