Pumbaa keeps Timon up all night to see the Porkeswanees, but them not sleeping attracts the Sandman.
“The Big No Sleep” begins by introducing Timon, a meerkat, and his warthog friend, Pumbaa.
At the start of the episode, Pumbaa sees that the night is finally here, meaning that there will be something unusual coming. An exhausted Timon comes back from work, complaining to his friend about him being up since dawn hunting for bugs. He gives Pumbaa the insects for him to eat while he goes to sleep. Before he does so, Pumbaa makes Timon make a promise, which is to stay up all night to watch the Porkeswanees, creatures with the wings of a swan and the bodies of a warthog which appear once every hundred years when their nocturnal migrations take over the jungle. After realizing that the Porkeswanees are coming tonight, Timon reluctantly agrees to watch them with Pumbaa since he promised to do so.
While the two are waiting for the creatures, Timon tries to stay awake, but keeps getting sleepy. He therefore paints eyes on a pair of glasses to make it seem like he’s not sleeping. While Pumbaa goes to use a restroom, Timon falls asleep, unaware of a dinosaur attack passing by. Pumbaa returns and asks Timon if he missed anything while he was gone, but finds his friend sleeping. Timon tells Pumbaa that him not sleeping is attracting the sandman, but the warthog insists that he tries not to fall asleep and watch the Porkeswanees with him since he promised.
Timon then gets an idea, which is to place a dummy of himself next to Pumbaa while he goes to bed. But when he hears Pumbaa talking about what a good friend he is to keep his promise over choosing to watch the Porkeswanees with him over sleeping, the meerkat feels guilty and runs back to Pumbaa, removing the dummy. Pumbaa then asks Timon if they will really be able to stay up all night to watch the Porkeswanees, which the meerkat replies that they will do so, sleep or no sleep.
Later, Timon and Pumbaa start to get sleepy. Timon decides to play some night music to help them keep them awake until Pumbaa makes him realize that it would attract the rest of the jungle. Timon then suggests that they read some horror comics. After Timon reads a comic about the Hideous Thing That Lurks in the Jungle, the Thing appears and asks the duo if they called for him. Timon and Pumbaa get terrified and run away from the creature.
Timon and Pumbaa realize that it’s getting late, but still refuse to sleep as they are still awaiting the Porkeswanees. As time passes, Timon and Pumbaa have a hard time trying to stay awake. The two then have a vision of inanimate objects making them sleep. Timon then stops the vision and says that he made a promise to Pumbaa and a buddy always keeps his words and that they are going to stay up all night to watch the Porkeswanees.
The sandman then appears and decides to use his magic sand to make Pumbaa fall asleep, but Timon covers him with the jungle sand. Morning then arises and the Porkeswanees arrive, with Pumbaa thanking Timon for keeping his promise.