"Quillber's Birthday Present" is the 35th episode of the first season of Wild Kratts, originally airing on PBS Kids on October 25, 2012. The episode was written and directed by Chris Kratt.
In this episode, while looking for a birthday present for Aviva on the African savanna, the Kratt brothers stumble upon an African crested porcupine. They follow it to its den, hoping to find some shed quills that could be used as part of a necklace.
The episode begins with a live action segment, in which the Kratt brothers get a good look at porcupines and their quills. Afterwards, they ask their "What if?" question and the show transitions into the cartoon segment.
The Kratt brothers are hang-gliding over the African savanna, looking for a birthday present for Aviva, when Martin crashes into Chris while trying to land his hang-glider, causing them to get thrown into a bur bush. Seeing how burs hook onto fabrics, the brothers decide to find a "creature invention". Koki and Jimmy, on the other hand, try to keep Aviva's birthday a secret while setting up the decorations, which include balloons. Meanwhile, Zach Varmitech explains to his Zachbots his plan to collect animals for some robots. However, the Zachbots have no power, so after plugging them into the charger, he heads off to collect the animals himself.
While continuing to search for a present, Chris gets poked by an African crested porcupine, which Martin names Quillber. Due to the fact that porcupines defend themselves with quills, which are actually hair used as a defense, the Kratt brothers think that porcupine quills would make a perfect present for Aviva. Koki even gives them the idea to use the quills in a necklace. Knowing that porcupines shed their quills all over the place, the Kratt brothers follow Quillber.
Jimmy finishes pumping helium into the balloons. He leaves the balloons alone after tying them down onto some logs. Zach takes advantage of the situation by taking the box of balloons and the helium cylinder.
The Kratt brothers reach Quillber's den. They pick up some quills and leave not long after meeting Quillber's mate and recently-born porcupettes, or baby porcupines. Once they get out, they notice balloons that originated from Zach. The Kratt brothers, and later Quillber, arrive at the Tortuga. When explaining the predicament to Aviva, Chris says "yeah, and with your balloons," and Aviva hugs Chris because he and the rest of the team remembered that it is her birthday. After Martin presents the raw porcupine quills, Aviva completes two Porcupine Power Discs. Aviva tosses the discs to the brothers, while Jimmy puts rocket boots under their boots. The Kratt brothers activate their Creature Power Suits. Martin destroys Zach's Zachbots while Chris pops some balloons, allowing the animals Zach has captured to fall safely to the ground. As a last resort, Zach hits Martin with his blimp, but the blimp gets punctured by Martin's last remaining quill, which causes his blimp to loop de loop out of view. Later, the Wild Kratts celebrate Aviva's birthday at Quillber's den. Aviva's puts on her porcupine quill necklace, and the Kratt brothers give a bark and root cake as a present to Quillber's porcupettes.
The show transitions into the ending live action segment, which shows the Kratt brothers talking about the differences between North American porcupines and African crested porcupines. Afterwards, they conclude the episode by saying "Keep on creature adventuring; we'll see you on the creature trail!"