Flappy Bob is a clown who was separated from his clown parents as an infant and was found by Sanderson and H.P as they were driving back to Pixie World after another failed thirty-seven-year plan attempt to take over Earth and Fairy World. When they found him, they attempted to use him for their new thirty-seven-year plan. They taught him that boring was fun so that they could make him run Camp Learn-a-Torium and take over Dimmsdale in a boring manner.
He became the owner of Camp Learn-a-Torium enforcing a strict policy of safety, resulting in the children becoming bored. He was the secondary antagonist in School's Out!: The Musical and later the second deuteragonist. At the end, he realizes his mistake and helps Timmy get rid of the pixies.
Even when he is shown as a baby, Flappy Bob is in clown make up along with his parents. However, after being turned into a cold boring businessman by the Pixies, Flappy wore no make up and appeared as a plain-looking man with a business suit. After he learned the true meaning of fun, Flappy Bob put his clown make-up and clothes back on.
After being found by the Pixies, thirty-seven years went by and Flappy Bob became a greedy, boring businessman taught to think that fun was boring and that boring was fun and no longer was the clown he once was. Eventually creating Camp Learn-A-Torium after the Pixies leave some blueprints on his briefcase after graduating law school. Then, shortly after Timmy made his wish that kids could take over the Earth it wasn't long before he learned that his camp was torn apart. Completely outraged, he signed a contract with H.P. and Sanderson to make the world boring and dull which he was described as fun, but it wasn't long until he overheard the Pixies gloating that they defeated the Fairies by making Flappy think boring was fun and remove everything that he thought was fun as boring. This makes Flappy realize that they were using him all along this entire time. So he returned to being a fun-loving clown and showed Timmy a loophole in the contract. He then helped Timmy put fun back on Earth which eventually got HP and Sanderson's attention.
Flappy Bob then notes that they lied to him about everything he originally thought was fun and were just merely using him. HP and Sanderson note that is true, but they still have the iron-clad contract Flappy signed. Flappy notes it is true that everything in the contract is binding, and that is why he wants to turn the Pixies' attention to some small print. It turns out that the contract says that Earth will be safe and fun as defined by Flappy himself and Flappy reveals that he defines fun as everything that is fun as it's supposed to be, meaning the Pixies have lost yet again.
Timmy then notes to the defeated Pixies that they shouldn't have sent Flappy to law school. After telling Timmy that he will pay next time, HP tears up the contract and restores Fairy World and Earth to how it was before. With the help of Timmy, Cosmo and Wanda, Flappy found his clown parents, disowned Camp Learn-a-Torium, and learned the true meaning of fun. Because of this, Flappy Bob is no longer considered a villain.