Courage, Muriel and Eustace are at Nowhere Wet World watching Jojo the Dolphin perform in his tank. However, Eustace is unimpressed and challenges the dolphin to a swimming race. The farmer fails miserably at doing so, so Eustace sets a rematch up for tomorrow and if Eustace loses, Muriel must pack her things and become JoJo's sidekick, much to Courage's chagrin.
At the house, Courage and Muriel begin training Eustace to become a professional-level swimmer. When all fails, Courage disguises himself as a therapist. He then proceeds to hypnotize Eustace telling him to break out of his hard outer shell and become his new self and be a better swimmer. It works, and Eustace, Courage and Muriel go to Wet World and Courage becomes terrified when he realizes Eustace must beat JoJo in a treacherous obstacle course.
Eustace and JoJo start and Eustace is competing well until the trainer cheats-when Eustace leaps up to the platform-the trainer bashes him with a bucket. Eustace returns to his old self calling himself a failure and losing horribly. Hurriedly and horrified, Courage runs to the side of the tank and tries to hypnotize Eustace agian, but instead, it hynoptizes JoJo and JoJo's suit explodes, revealing a tiny and puny fish. Then the trainer becomes hynoptized and his costume explodes revealing a lizard underneath. Eustace wins and returns home.
In the end, Eustace is shown swimming in a tank in the middle of the living room, but it breaks after Eustace beats on the glass and water explodes everywhere.
- First appearance of Jo-Jo and his Trainer.
- Other characters that made a cameo in Wet World are Kitty, Conway, Di Lung, Evil Empress, Seagull, Parachute Lady, Elephant, Rumpelstiltskin, Giraffe, Waitress, Beared Man, Rich Guy, Shirley the Medium, Space Chicken, Floyd, and Le Quack .
- Jo-Jo's "inner-self" was a fish and the Trainer's was a lizard.
- "Sloop John B" by The Beach Boys can be heard at 4:13.
- This and Farmer-Hunter Farmer Hunted are the only episodes in which Eustace is portrayed as the main protagonist. Interestingly neither title refers to Eustace by name.
- Despite dolphins being mammals, Eustace repeatedly refers to Jo-Jo as "a stinking fish" throughout the episode. This is ironic considering Jojo's "inner-self" IS a fish!
- Evil Empress appear even though she dead in the previous episode, Squatting Tiger, Hidden Dog.