In Legend of Korra, Tenzin’s bison is named Oogi, and in the first trilogy of Avatar: The Last Airbender graphic novels, Sokka says something similar.
Legend of Korra showed that not only was Aang no longer the last Airbender, but also that Appa was no longer the last sky bison. In fact, Aang’s son Tenzin has a bison of his own named Oogi, and the Avatar: The Last Airbender comics provide a clue as to what may have inspired Oogi’s name.
While all of the sky bison were initially believed to have been wiped out during the Air Nomad Genocide, the inciting incident of the Hundred Year War, Aang discovered a new herd in his adventures after ending the war, leading to new populations of bison growing at the air temples. It was also revealed in Legend of Korra that a herd of bison was secretly being cared for by the Bhanti Tribe on an island in the Fire Nation. Oogi is descended from one of these herds, which is a different subspecies of sky bison than Appa judging by the different horns and arrow designs. This would make sense given that Appa, much like Aang, was frozen for 100 years while his species continued to evolve during that time.
Oogi may have come from a herd of bison found by Aang, but his name was actually inspired by another member of the original Avatar crew: Sokka. Avatar: The Last Airbender – The Promise is the first of several graphic novel trilogies that follow the events of the show. It picks up pretty much exactly where the show left off – with Aang and Katara kissing. But the romantic, heartfelt moment that ended the show is used as a comedic bit to kick off the comics when Sokka walks in on the two smooching. Aang is embarrassed, Katara is mad, and Sokka is just grossed out. “As my sister, you really shouldn’t be kissing anyone in front of me!” he says. “It’s your sisterly duty to avoid giving me the oogies!” Katara is quick to point out Sokka’s hypocrisy – he and Suki don’t exactly shy away from PDA – but the important thing here is that Sokka says “oogies,” which is eerily similar to the name of Tenzin’s bison. It may seem like just a coincidence – until you see just how often Sokka says it.
Throughout the trilogy of The Promise, Katara and Aang are very open about their feelings for one another, often kissing, hugging, and calling each other sweetie – a refreshing change since it took them all three seasons of the show to finally admit their love for one another. For Sokka, however, it’s pretty uncomfortable. Whenever Aang and Katara get romantic around Sokka – which is pretty often – he says they’re giving him “the oogies.” In fact, he says it so much that Katara gets fed up with it. “I am so sick of hearing about your stupid ‘oogies’ Sokka!” she yells. “I don’t even know what that means!” Toph helps Katara understand by licking her hand, causing Katara to yell “oogie!” herself.
While it’s never explicitly confirmed, it can’t be a coincidence that the name of Tenzin’s bison is essentially the same as Sokka’s exclamation of disgust. Knowing Sokka, he probably kept saying “oogies” well into adulthood just to annoy Katara. After all, we know Toph kept calling Aang twinkle toes even when he was 40 years old. It follows that a young Tenzin would hear his Uncle Sokka saying oogie all the time and use it as the name for his bison, because in a weird way, the word oogie represents the love between Tenzin’s parents.