Kwazii's Special Birthday Surprise! is the 26th episode of Season 4.
It's Kwazii's birthday and Jake, Sofia, and the gang are planning a surprise party for him in Never Land. While the Octonauts are keeping Kwazii distracted with missions, Sofia and Vivian collect diamonds and pearls to make special gifts, Izzy, Cubby, and Skully make the food, Gaspard, Lisa, and Henry Hugglemonster bake the pirate cake, Zooter and Ellyvan deliver the invitations, Sharky and Bones practice their music, and Minnie, Cocoloco, and Daisy get the decorations ready, and Mickey even gets the fireworks ready, but meanwhile, Jake tries to find the perfect gift for Kwazii, until he stumbles upon two golden sand dollars and then makes two friendship bracelets for him and Kwazii.
The episode begins with Kwazii still sleeping in his bed when he wakes up to see the calendar and suddenly smiles with excitement! He goes to the kitchen through the Octo-Shoot and after arriving at the kitchen, he finds a plate full of birthday cake flavored pancakes, a little vase with a rose, a box with a shiny pearl from his grandfather, and a birthday card.
After finishing his birthday breakfast, he goes through the Octo-Shoot again to the HQ. Kwazii arrives to say good morning to the other Octonauts and reminds them that it's his birthday today, only they were too busy working on computers and pushing buttons or just reading books. Kwazii tries to get them to remember his birthday, but they just ignore him and kept on doing their work. Kwazii becomes depressed but luckily Captain Barnacles decides to cheer him up with a mission. After Kwazii leaves to go on his mission, Captain Barnacles and the crew being to work on their real job: preparing Kwazii's birthday party in Never Land!
While the Octonauts are making the decorations and birthday presents, Barnacles presses a button to turn on the screen only to show Jake gliding in the sky looking for the perfect present for Kwazii. Meanwhile, Sofia and her best friend, Vivian are making presents with pearls and diamonds for Kwazii in her room and at Dolphin Shores, Sharky and Bones are practicing their new birthday song "Yo Ho Happy Birthday Kwazii!" for the party which has Captain Hook covering his ears and Mr. Smee dancing to the beat. Captain Hook asks them why they're singing that birthday song and Bones explains that it's for Kwazii because it's his birthday today.
Kwazii in the Gup-B hears the music and dolphin chattering from Dolphin Shores and catches sight of Sharky and Bones singing. He goes to the Jolly Roger to hear the music but Sharky and Bones quickly hide their instruments as Kwazii approaches. He asks if they're playing their song for his birthday, but Sharky and Bones lie that they were only singing it to the dolphins just so they can keep the party at Never Land a secret. As Kwazii leaves the Jolly Roger feeling once again depressed, Sharky and Bones continue their song.
After looking for Kwazii's present for only 2 hours, Jake decides check on Gaspard, Lisa, and Henry who were helping the baker make Kwazii's birthday cake at the Disney Junior Town bakery. He looks at the cake which was orange and gold and had cake decorations of Kwazii, doubloons, waves and dolphins on it and Jake gives them a thumbs up when he hears a knock on the door. Outside was none other than Kwazii!
Quickly, Gaspard, Lisa, Henry, and the baker hid the cake in the closet while Jake opened the door for his best friend. As Kwazii entered, he greets Jake and tells him that he thought he smelled birthday cake but Jake lied to him that he and the others were not baking any cake but Kwazii just sniffed the air again and insist that he does smell cake. Without thinking, Jake tells him that he's not smelling cake but just cupcakes so he takes one from a cupcake stand and stuffs it in Kwazii's mouth then pushes him out of the bakery through the door. After he leaves taking the cupcake out of his mouth and sadly eating it, Jake and the others continue finishing the cake but the third cake layer fell off when Lisa accidentally bumped into the cake. Gaspard and Lisa shout out "Catastrophe!" but Jake and Henry have no worry so Jake take the decorations off the fallen cake layer and put them on the second layer. After helping with the cake, Jake reminds Gaspard and Lisa to come to Never Land at 5pm and says goodbye when he leaves the bakery to continue his search for Kwazii's present.
Kwazii (Narrating): Kwazii's Special Birthday Surprise!