Ugh! I cannot believe how disappointed I am about The Last Airbender movie. The original, cartoon version is a whole lot better than the movie one. I of course understand that the whole Book 1: Water is too long to fit in one movie and it is natural that some scenes and parts be removed, but to CHANGE some of the parts is another thing.
One, let's start with when Katara and Sokka find Aang in the iceberg. In the cartoon version, Katara is still learning water bending and pretty much sucks at it. She and Sokka are having an argument, and while Katara is really mad at Sokka, while gesturing with her hands and arms at Sokka, she is unintentionally water bending and manages to destroy one whole iceberg, leaving the sphere where Aang is inside. Katara uses Sokka's boomerang to open the sphere, and they find Aang. This part of the cartoon shows that Katara has the potential of becoming a great water bender, as she has the strength but not the skills yet as she never received any formal training.
In the movie version, Katara and Sokka are out hunting for food, and they notice something odd in the ice. Sokka cracks the ice, sending them running, then the sphere where Aang is shows up. Katara uses the boomerang to free Aang from the iceberg, and Gran-Gran explains what the spirit world is, knows that Aang is the Avatar, and encourages the siblings to set out on a journey with Aang.
From this part, I already hated what they did to Katara. She becomes just another character, because the spunk in her is lost, not to mention the fact that Sokka is not at all funny in the movie and is even more serious than the cartoon version of Katara. Don't get me into explaining what happened in the Fire Nation prison where earth benders were held prisoner - that will be for another post, as well as for who teaches Aang and Katara water bending.
In the movie version, Aang said he ran away because he was upset when he was told that since he was the Avatar, he can't have a family of his own. Then, how will the battle between good and evil in Prince Zuko's heart be explained, especially since he is actually the great grandson of Avatar Rokku if avatar's aren't allowed to marry and have families of their own? The real reason why Aang did run away was because he was going to be sent away all over the world to learn the different elements, and he did not want to be separated from his mentor monk whom he sees as a father. It was also because of the fact that the identity of the avatar is not to be revealed until he/she is 16, but Aang knew he was the avatar since he was 10, hence he was still childish and impulsive.
Uncle Iroh is not fat, and Gran-Gran's love story with the water bending master from the North Tribe will be gone, and Katara's heart-filled speeches about how the earth benders should stand up and fight is gone too.
One thing I did notice about the movie is that the fire benders had bonfires everywhere and used those to bend fire. Unlike in the cartoons, they can just make fire appear like it was air, in the movie, it wasn't the case. In all fairness, I wondered about that while watching the cartoons, because Katara needed to bring water with her wherever she went so she could bend, and even resorted to using her own sweat for water bending, as well as getting the water from plants. But how could the other fire benders just shoot fire from out of nowhere? I guess the movie tried to justify that part, but they sucked everywhere else. They couldn't even pronounce Aang right. >.<