One night, Jake is attacked by an army of sewer trolls. When he tried to call Fu for help, it shows Fu was playing a card game with Esmerelda, a Goblin, Shark Lady, and an Abominable Snowman.
At the DMC, Fu got his animal guardian license going down (means it was expired again) and Jake got a new magical guardian who was a talking monkey named Bananas B. Meanwhile, the necklace that Jake got from the trolls shows that the necklace belonged to Chang.
Chang escaped from prison. The next day, Jake went to school and he forgot about Fu's test. Fu had to do the test with an old Gnome named Mister. Krunkers. 1st test: Fu and Krunkers both had to defeat 4 hobgoblins, but Krunkers is very dumb so he hits Fu with a huge wooden club. 2nd test: Fu told Krunkers to had a pitch of Leprechaun Dust in the orange potion, but yet again Krunkers did a bad mistake on purpose so he adds the wrong ingredient in the potion and turns into blue color, resulting in a huge explosion. Thus, Fu failed the test.
When Jake, Spud, and Bananas arrived back at the shop, Chang suddenly appeared out of nowhere and says "Lao Shi's grandson, we meet again". The sewer trolls attacked the heroes and it was learned the trolls were working for Chang. Chang was about to kill Spud by crushing his head, until Trixie stopped her. Chang blasted sphinx hair nets and wrapped them on Jake. Bananas B joined with Chang and the two villains escaped after they captured Jake.
Fu is walking with sadness and he had Jake's back. At a carnival, Jake releases himself and killed all of the trolls, but Chang was about to kill Jake, until a blue beaker hit her. It freezes Chang and she fell. It was Fu Dog, he then rescues Jake. Chang and Bananas escaped, but she said she would come back for Jake and his grandfather.
At the DMC, Jake was telling the creatures that Fu was loyal and a friend and his licensed was returned to him. The episode ends where Jake and his pals were playing a card game.
Later, Fu is telling about other animal besides Shark Lady. There were other magical animals such as Legal Eagle; Lounge Lizard; and a Duck with Goose Pimples which had a habit of popping pimples that frightened Fu.
- The title is a pun on "Nobody's fool".
- Fu breaks the fourth wall at the end.