King Buffo was the king of the bullfrogs that invaded the Bagges' house and forced them to build a new pond in the middle of the living room.
In the beginning of the episode Feast of the Bullfrogs, King Buffo and his bullfrogs once lived in a pond, but it then dried out on a very hot day. King Buffo declares that it is time to find a new pond to live in. So at night, all the bullfrogs moved into the Bagges house. Then when the frogs surrounded Eustace, Muriel, and Courage, Buffo then comes in with his bodyguard and his advisor. King Buffo tells the Bagges to dig a pond at their house. The Bagges at first don't understand him, but King Buffo's advisor explains that the bullfrog king claims the Bagge house as their new home and therefore ordering them to dig a pond now. Muriel tries to tell them that the frogs can't dig a pond, but Buffo says, "Not us, you!" And then the frogs chanted, "Dig pond!," but King Buffo manages to silence his subjects. Eustace couldn't stand to see all the bullfrogs and tries to go upstairs and get his mallet. Unfortunately, Buffo ordered his bodyguard Bluff to stop Eustace, making him fall down the stairs. Then he ordered most of the bullfrogs to surround Muriel when she demands that the bullfrogs must go. Finally, Buffo tells Courage to dig a pond, which he does.
After Courage finished digging the hole, the frogs are delighted that they finally have a pond. King Buffo then says that the pond is dry and tells Eustace to fill the hole with water. But when Eustace refused, Buffo beats him up with his tongue and then orders Muriel and Courage to get lily pads. As Buffo's bodyguard is watching them, Courage and Muriel tries to look for some lily pads. When they couldn't find any, the bullfrog bodyguard growls menacingly at them. Horrified by this, Courage takes out a sponge from the drawer and it lands into a sink full of water. Seeing this, the bodyguard leaps on the sponge and decides that the sponge is a better substitute for a lily pad. After Eustace fills the hole with water and Muriel dumps the sponge into the water, Buffo then tells Eustace and Muriel to live like frogs and hop like frogs. At first Eustace and Muriel refused, but Buffo's bodyguard forced them to do it. Then the king orders Eustace and Muriel to croak like frogs and eat like frogs which they forcibly do. This also makes Courage faint. Then King Buffo declares that the bullfrogs' new pond is open. All the frogs begin to celebrate with a party. When Courage came to, he is teriffied to see what the frogs have done. King Buffo's advisor then asks the king if he wants a celebration feast. The King agrees and then orders Bluff to get many flies by using Courage.To get the flies, Bluff first pours honey all over Courage and then takes him outside where he whistles for the flies to get the honey. The flies then spreads all over on Courage. Bluff then takes Courage back inside where King Buffo's advisor gathered up all the flies and spread them on Eustace and Muriel's legs where he says that the king is going to have human legs for his feast. Realizing that Buffo wants to eat Eustace and Muriel, Courage tries to talk to them about this. But they only answer by croaking like frogs. Seeing that this is going nowhere, Courage decides to get rid of the frogs by himself by using the jar of honey and a box of flypaper. First he goes outside in the backyard and pours honey all over himself. Then he lets all the flies cover him and eat the honey while Courage captures the flies with a bunch of fly paper. But when Courage comes back in the house, he becomes terrified that the frogs are starting to cook Eustace and Muriel. Using the flypapers as a set of wings, Courage hovers up to ceiling where he begins to staple all the fly papers while on a chandelier. Then Courage whistles for the frogs to see. The bullfrogs sees the flies and say they are appetizers and then shoot their tongues at the flypapers getting them stuck. Then Courage uses the chandelier rope to tie up the frogs and pulls them by the tongue. As he pulls them outside, Courage swings the bullfrogs and throws them somewhere far away. With his worshippers gone, King Buffo is forced to find some new worshippers. But as he leaves, he says to Courage "Stupid Dog." At the end of the episode, Buffo then became a baseball player.