"Peewit Meets Bigmouth" is a Season 3 episode from the Smurfs cartoon show.
Peewit is in the library of Homnibus the sorcerer, studying through his books so that he could be a wizard, while the sorcerer himself entertains Papa Smurf in a game of chess. Peewit thinks he has mastered a spell that could summon birds from thin air when he hears what he assumes is a woodpecker pecking at the door, but it is actually his friend Sir Johan who came by to summon Peewit to return to the castle. He tells Peewit that King Turgon has arrived at the castle to sign a treaty with the king, so Peewit reluctantly follows along on his goat Biquette while he reads one of the spell books he has "borrowed" from Homnibus. Johan tells Peewit to ride faster because the king specifically wanted him to entertain King Turgon, so Peewit summons Biquette to gallop faster.
At the good king's castle, the king finds himself with the difficult task of not only having to sign a treaty with King Turgon without risking a war, but also having to entertain King Turgon's son Prince Dax, who seems rather bored being at the castle. Peewit decides to take on the task of entertaining Prince Dax, which at first he tries with a shell game using goblets, though Prince Dax is more interested in having Peewit be part of his "shell game" when he tosses the cover of a chicken roaster onto Peewit's head. The young jester sees that taking care of the bratty prince is going to be tough work, but nonetheless he proceeds with his next attempt to entertain Dax by creating a formula for a spell to turn a table into a turtle. Dax, on the other hand, wants to play tag and slaps Peewit, saying that he's it, and making the bowl that he mixes the formula with fly out of his hands and land on top of Dax, which ends up turning the young prince into a chicken.
Seeing what trouble Prince Dax has brought upon himself, Peewit goes to his spell book to find a spell that will turn the chicken back into a prince. Prince Dax, however, is too impatient to wait and ends up running out of the castle and into a field full of chickens, where Peewit spends his time looking for the prince while the prince himself sneaks out of the castle. Peewit finds and captures a chicken that he thinks is the prince and takes him back inside the castle to attempt turning him back into a prince, only to fail when the chicken he uses the reverse spell formula on turns blue instead of into Prince Dax. The young jester eventually gets the aid of Johan, who helps round up as many chickens as possible so they could find the prince before King Turgon finds out that his son is gone.
Out in the forest, Bigmouth the ogre is carrying a sack with him, hoping to find a chicken to make a chicken stew out of. Prince Dax sees that he is a chicken and tries to hide in the bushes so that Bigmouth wouldn't find him. But then Bigmouth smells the chicken nearby and lifts up the bush to reveal Prince Dax as a chicken underneath. Prince Dax quickly runs for his life while Bigmouth chases after him, thinking that he's a chicken.
Meanwhile, Papa Smurf is with a few of his Smurfs out in the forest collecting peat moss to bring back to the village when they hear the sound of a runaway chicken coming. They dive into a bush for cover and watch as a chicken with blue eyes is running away from Bigmouth, who eventually catches the chicken after it hides itself inside a hollowed log. Smurfette finds her heart going out to the chicken that Bigmouth captured and says that they need to do something.
Back in the king's castle, Peewit tries many times to cast the reverse spell on the chickens, only to find that it doesn't work because none of the chickens are actually Prince Dax, and Peewit and Johan have gone through every chicken they can find. Peewit only wishes there was some way he can tell which chicken is Prince Dax, and Johan comes up with what he thinks they can tell the Prince Dax chicken from the others: Prince Dax has blue eyes, while the other chickens don't. They tell the king what has happened to the prince before they take off into the forest to find the blue-eyed chicken, leaving the king with the difficult task of keeping King Turgon stalled and in the dark about his son until they return.
As Johan and Peewit split up and search through every part of the forest to find Prince Dax, the Smurfs see Bigmouth prepare for his chicken stew with ingredients that make Smurfette turn her head in disgust. Papa Smurf tells his little Smurfs that they need to find some way to distract Bigmouth so that they can rescue the chicken. In their search for something they can use as a distraction, the Smurfs run into Peewit, who is surprised to find out that the Smurfs are rescuing the same chicken he is trying to find. Together they work on a plan: as Bigmouth now has the broth ready to cook the chicken in, Peewit goes to tell the ogre that he can prepare something better for him to eat, which are Smurf dumplings. To demonstrate, Peewit uses a bit of flash powder on the chicken, which then turns into two Smurfs that Bigmouth is ready to put into the stew. But Peewit tells Bigmouth that they need to be turned into dumplings, and so with a puff of flash powder he turns them into two blue dumplings (which are actually painted rocks that Papa Smurf and Smurfette swap Brainy and Clumsy for). Bigmouth tries to take a bite out of one of the dumplings, only to find that it is hard. Peewit says that they need to be cooked for one hour before eating, and so as Bigmouth tends to his Smurf dumpling stew, Peewit and the Smurfs get the chicken freed from his bonds before the young jester thanks them for their help and rides back into the castle with Prince Dax.
Back at the castle, King Turgon is at the end of his patience with the king now that he has the treaty signed and he is waiting for his son Prince Dax to be returned to him at once. Soon Peewit comes riding into the castle with Prince Dax still as a chicken, and in his private chambers the young jester uses the reverse spell to change the prince back to normal. King Turgon bursts into Peewit's chambers to find his son eager to tell him about the wild adventure he had with Peewit, which his father likens to the boy having a vivid imagination, thus letting Peewit off the hook. After the king, Johan, and Peewit see the royal father and son ride off happily with each other, Peewit says that he wishes he could be there to see the look on Bigmouth's face when he tastes the "Smurf dumplings". And about an hour later, as Bigmouth takes the "dumplings" out of the stew to eat, he says that the "dumplings" are not soft but they are not bad.