Aang

Aang is one of the main characters. He is the last airbender and is also the Avatar. He is presumably a master of airbending and has basic waterbending skills. He has also been shown to do some firebending in the episode "The Deserter" and has recently begun aqcuiring skill in earthbending. Aang is the shadowed figure performing airbending in the opening sequence.

Life before Aang froze himself
Aang, a 12 year old Air Nomad, never wanted to be the Avatar. He just wanted to be a kid who could have a lot of fun. But when you find out that you're the legendary Avatar, nothing stays the same. Though technically he was supposed to have been told of his fate when he turned 16, the five monks of the Southern Air Temple told him early because they feared war was on the horizon. Aang reluctantly accepted, for a while anyway.

But a conflict of interest between the monks resulted in Aang being transferred to the Eastern Air Temple to separate him from his caring guardian, Monk Gyatso. However this was the last straw for Aang, and so one night before he was moved he ran away with Appa, his flying bison. They got caught in a horrible storm and were thrown into the ocean. Their only means of survival was for Aang to encase them both inside a large air pocket, which eventually froze over and became an iceberg.

Aang in the modern time
They stayed trapped inside for 100 years, until Katara and Sokka discovered and freed him. He became fast friends with Katara, but it took more effort until Sokka began to trust him. Naturally, Aang remained the same as he was when he was last awake 100 years prior, but his outlook begins to dampen as he adjusts to just how much the world has changed without him. While he was frozen a bloody war between the Fire Nation and the other nations broke out, which is still being waged when he awakens. You can see his attitude slowly begin to change as he sees more of the destruction from the war, and all the people who've suffered because he wasn't there to prevent it.

Traveling with his now good friends Katara and Sokka, along with pets Appa and Momo, Aang is exploring the world in hopes to finish his training and truly become the Avatar. In order to do so, Aang must master Waterbending, Earthbending, and Firebending, along with furthering his Airbending skills. Although because the Avatar is considered a 'great bridge between the natural and spirit worlds', he also has to learn about being the Avatar and using the unique powers that come with that title. Only when he has finished his training and is truly ready will he stand a chance of returning peace to the world and stopping Firelord Ozai. But unfortunately, he only has until Summer's End, lest Ozai becomes unstoppable.

Aang's personal life
Aang, before the iceberg incident, trained at the Southern Air Temple and was raised by monks along with a handful of other airbending boys. He was the pupil of Monk Gyatso, master Airbender and a kind fatherly-like teacher. After Aang was told that he was the Avatar, the other boys basically excluded him, so Gyatso became his only real friend there. In the Earth Kingdom city of Omashu, Aang had a friend named Bumi who taught him to always keep his mind open to possibilities.

Aang is energetic, a vegetarian, and loves animals and riding them. He feels horribly guilty almost every time he comes across a place that was destroyed because the Avatar wasn't there to save them; and is always looking for adventure despite his duties as an Avatar-in-training. He's the only known Airbender left in the world as the Fire Nation killed all of the others, and currently knows how to use all the elements, but is only a master in Air- and Waterbending. However, when his life is threatened, he is able to call upon the Avatar spirits and use their power. But doing so requires a lot of energy, and Aang usually collapses afterwards leaving him open for attacks. Good thing he has Katara and Sokka to back him up. Aang has a flying bison named Appa and a winged-lemur named Momo, and together they represent all that is left of the Air Nomads. Aang also has a pretty-big crush on Katara.

Personality
Aang is still a child (though technically he is 112 due to the 100 years in the iceberg) so he has very childish emotions and does very childish things. Aang has a kind heart though his impatience does get him into trouble. He made fast friends with the Waterbender Katara and her brother Sokka. His other companions include Momo the Flying Lemur and Appa the flying bison.

Katara
Katara is the first person Aang met when he was unfrozen in the South Pole and one of his dearest friends. Katara is a water bending master from the Southern Waterbending Tribe. Her abilites include water whips, healing, and the ability to freeze water into ice. Before she met Aang, she was Sokka's younger sister and played the maternal figure. She would do everything that her mother did before she was killed. She discovered Aang when she unknowingly used waterbending while she was yelling at Sokka. After meeting Aang, he's taught her that life is more about fun. When Aang was ordered to leave the South Pole after tripping a flare inside a forbidden Fire Nation ship, Katara willingly wanted to go with him but she stayed behind. When Zuko attacked, Aang returned only for Zuko to take him. Katara and Sokka followed Aang and joined up with him after defeating Prince Zuko. For the time, Aang and Katara seem to have crushes on each other. It is further exposed during Episode 2 of the 2nd season when Aang and Katara "kissed" in the dark while in the Secret Tunnel.

Sokka
When Sokka first met Aang, he thought he was a spy from the Fire Nation. So, his relationship with Aang had a rocky start. He's Katara's older brother and leader of the tribe since his father left. His weapon consists of his warrior instincts and his boomerang. Sokka's hate for him went further when he discovered Aang and Katara returning from the crashed Fire Nation ship. While Aang was banished, Zuko attacked and Sokka stood no match. Sokka has a deep hate for the Fire Nation and Zuko. Sokka is considered the comic relief of the team since he is often the one taking the bad end of some things. Sokka has two girls he seems to be in love with, Princess Yue from the North Pole and Suke from Kyoshi Island. With Yue deceased, it seems Suke is the only girl left.

Appa
Appa is Aang's trusted 10 ton flying bison and their mode of transportation. While he may be a bison, he has two extra back legs and a beaver like tail. Appa just gives off low growls when he expresses his emotions. He was the only other creature with Aang when he was frozen in the glacier. Once on Kyoshi Sokka said "That was really convincing, still hard to argue with a 10-ton magical monster"

"Appa is a 10-ton flying bison, i'm sure he could figure something out"- Aang in The King Of Omashu

Momo
Momo is the frisky and cute flying lemur of Aang's team. He is considered a pet to Aang and one of his treasured friends. At first, Sokka was hungry after Aang accidentally used his beef jerky as campfire wood and tried to eat Momo. He got over it and Momo brought food for him. Momo often steals things like food when no one's looking. His physical appearance is a lemur with giant bat-like ears and bat like wings he keeps under his arms and open when he flies.

Toph
Often reffered to as the "Mysterious Girl" from Aang's vision in the Mystic Swamp, Toph is a young blind girl who belongs to a very wealthy family. When Aang met King Bumi on their second visit to Omashu, Bumi told Aang he must find an Earthbending teacher who can "feel and listen" to the Earth. The only things Aang recognized from his vision of Toph was her flying boar(the family sign) and her laugh. He first met Toph at the Earth Rumble 6, an Earthbending Tournament. Her identity was the Blind Bandit because of her skills and she was the current 2 time champion. Even though she is blind, she can sense people from afar by feeling them in the Earth and can attack before they even notice her attacking. She calls it "seeing with her feet". She was being trained by the towns best Earthbender while being kept at level 1 by her parents orders, but she has even surpassed her teacher with her skills which she kept secret. When they first met at the tournament ring, Aang "defeated" Toph when he was trying to talk to her which was caused when he used airbending as self defense and knocked her out of the ring. She was kidnapped along with Aang when the host of the tournment discovered Aang didn't beat Toph with earthbending and believed it was a scam set up by them both. While Toph was freed by returning the prize money, Aang was freed by his friends and watched as Toph defeated all of the Earthbenders attacking her. Later, Aang is told never to return to their home. This caused Toph to give off a small tear, and it may reveal she has a crush on Aang. Before Aang left, Toph convinced Aang that her father "gave her permission" to travel with them, while in reality she ran away from home making her father believe Aang kidnapped her. She currently is journeying with Aang, Katara, and Sokka as Aang's Earthbending teacher. Even though they started as rivals, they have now become close friends.

Voice actor
Aang was voiced by Mitchel Musso initially in the series two part pilot The Avatar Returns Part 1: The boy in the Iceberg and The Avatar Returns Part 2:(no subtitles) but afterwards was replaced by Zach Tyler Eisen from The Southern Air temple onward