Bumi is the king of the city of Omashu, a large city in the Earth Kingdom. Before the War, Bumi was a friend of Aang's. As of Avatar: The Last Airbender, he is the only surviving friend of Aang's from back then.
He is a member of the Order of the White Lotus, an ancient group that ignores the social barriers of the nations. This group works for peace throughout the world, and to do this, they join together with their bending powers.
Despite his strange and eccentric personality, Bumi carefully plans out almost every move he makes. This is how he easily takes back Omashu from the Fire Nation when they take over during the series. He waits for exactly the right time before he strikes and uses his Earthbending to take back his town.
He is also rather comical, often making foolish statements. For example, during his testing of Aang, he enjoys giving him tests that seem like they'd be easy...however, these tests are usually rather tasking and difficult. He also exclaims that "all old people know each other" when Sokka tries to figure out how the members of the Order of the White Lotus know each other, and doesn't explain exactly how they do. He also notices that an "important member of the group" is missing during this same time. He then asks where Momo is, despite Momo and Aang both missing, to tease the group. It is very possible, however, that he is genuinely worried about Momo, and barely notices Aang.
Being the king of Omashu, it is assumed that Bumi has many friends. However, he only has a truly defined relationship with a few people. He also considers some people his friends that he has showed very little interaction with (Momo, for example).
Before the war started, Aang and Bumi were the best of friends. Aang would frequently visit Bumi in Omashu and they would ride the mail system, thinking of it as one big slide. Aang always thought Bumi was crazy and referred to him as a 'mad genius'.
After Aang awoke from the iceberg one hundred years later, he finally was able to make it back to Omashu, where he was able to talk to Bumi again. After finally figuring out who he was, you could tell the love they have for each other as friends was still present and that Bumi's inner-child was still alive and well.
Flopsie is King Bumi's gorilla goat pet. When Flopsie is first revealed, Aang is trying to find an Earthbending teacher. After he finally figures out who Flopsie is, you could tell him and Bumi have a free and loving friendship. Flopsie may look opposing, but he is kind at heart.
|Bumi is a self-proclaimed master Earthbender, telling the group that he is the best Earthbender that they will ever see. Despite Toph making the same claim later in the show, this is very possible. Both of them have techniques exclusive to themselves. For example, Bumi can bend jennamite, a strange substance that encases the victim. He is also able to bend without touching the earth itself, and is able to move incredibly large bits of earth.|