The Kelp Monster attacks the gang with his pals Captain Pescado and the Octopus Monster. The Kelp Monster got on board with the Captain Pescado and the Octopus Monster. He was sleeping in the control center, until the Octopus Monster chased Shaggy and Scooby and the Kelp Monster woke up and chased Velma. The Kelp Monster and his pals found Scooby, Shaggy, and Velma in a sunken ship. The 3 ghosts were captured. Pescado was 1st Mate Carp, Kelp Monster was McFinn, and the Octopus Monster was McGil. The 3 criminals were taken to jail.