"Big Top Breakfast" begins by introducing a young circus monkey named Simon. At the start of the episode, Simon and his father are in a plane that is on its way to a circus, with Simon practicing his act. The act, sadly, ends in failure, making Simon believe that he is not good at being a circus monkey, but his father tells him "spotlights will go on him one of these days."
Meanwhile, the clown pilots practice some stunt flying erratically to make it their circus' attraction, but they cause Simon and his crate of circus stuff to fall out of the aircraft by accident. Meanwhile, Shenzi, Banzai, and Ed are searching for breakfast. While the hyenas talk about their hunger, Simon's crate lands on the trio, with Simon hearing them talking. When he tries to follow the voices to see who it is, he meets the hyenas, who are about to devour him.
Banzai almost eats Simon until he is stopped by Shenzi, who is then stopped by Ed, as they argue over who gets to eat the monkey. The trio then get so distracted by each other that they realize that Simon escaped them. The monkey finds himself in a jungle where he runs into other animals, which he runs away from in fear. Meanwhile, the hyenas try to come up with a plan to get Simon back to them. Shenzi and Banzai criticize each other's ideas, they see Ed playing with the circus stuff, making Shenzi plan on making Simon believe that he is in a circus performance, knowing that it is a perfect way for them to catch and eat the monkey.
Simon hears circus music playing and runs to where the hyenas are. The hyenas make Simon do different kinds of circus tricks. For the final act, Simon has to dive into a pot. When he does so, the hyenas cheer for their plan to have worked. But then, Simon manages to come out from the bottom of the pot. The hyenas see that Simon escape and they go after the monkey.
Simon outsmarts the trio by telling circus jokes while sitting on a ball. When the hyenas stop laughing, they continue to chase Simon, who falls and lands into a cannon. When Banzai pushes a button labeled launch, Simon gets launched out and gets back in the plane, where he reunites with his father.
The hyenas are dismayed by Simon's escape. While they talk about their hunger once again, Banzai mentions that he could eat a blue whale, making the said whale fall on the trio.