The Sea Monster is a minor villain from the adventure video game King's Quest V: Absence Makes the Heart Go Yonder. It is a large black sea creature that waits for ships to come by so it can destroy them and their crew.
The Sea Monster is encountered if the player is in the wrong direction on the sea. Once encountered, the Sea Monster will attack the ship and Graham and Cedric are killed.
The Sea Monster cannot be killed in the game and since it is avoided when Graham makes it to Mordack's Island, it is still alive and still roams the sea in search of prey.