The Depths of Cousin Fethry!

Huey and Dewey have Launchpad take them to visit Donald’s oddball cousin, Fethry Duck, whom they believe is a scientist working at one of Scrooge’s marine stations. However, they eventually realize he is just the station’s caretaker and turn to leave, but are attacked by a sea monster. In the end, Huey calms the creature by singing to it and Fethry realizes it is actually his pet krill, Mitzi, who was mutated by hydrothermal vents. Afterward, Fethry decides to become a real scientist and leaves with Mitzi while the boys meet up with Launchpad, who had his own adventure.