Tonton Streaming DuckTales (1987) S1E64 - All Ducks On Deck

Donald makes up a story about being a hero to the nephews. They stow away in the Navy and try to make him a hero. Meanwhile, The Phantom Blot has a spy infiltrating the Navy while he has Scrooge McDuck and Launchpad McQuack as prisoners on Cat Island after they go to investigate Scrooge's fishing fleet there.