The movements that Earth Benders use to control the earth are based on the Hung Gar style of Kung Fu.
The Fire Bender movements are designed after Northern Shaolin Kung Fu.
The Water Bender movements are designed after Tai Chi.
The four Chinese characters above the title translate to, "The Divine Medium who had descended upon the Mortal World."
Almost all of the animals in the show are a combination of two animals. Appa is half bison, half manatee. Momo is half bat, half lemur.
Airbending is based on a fighting style called Ba Gua.
Katara's name was originally Kya in the unaired pilot episode, but was changed before the start of the series proper. However, Kya was used for the name of Katara's and Sokka's mother later in the series.
The calligraphy on the top and bottom of the map form a rhyming couplet when read aloud in Chinese. The characters at the top read "Powers are divided into four," while those at the bottom read "The world is guided by one."
During the opening credits, silhouetted figures are shown demonstrating the various bending styles. The figures are recognizable as characters from the series: The Waterbender is Master Pakku, the Firebender is Prncess Azula, the Airbender is Master Gyatso, and the Avatar shown to demonstrate all four elements is Avatar Roku, the Avatar before Aang. The only figure who does not appear in the series is the Earthbender who has been revealed by the creators to have been the original Earthbending teacher for Aang before they thought of Toph.
Mako, who played Uncle Iroh, passed away in the middle of recording his parts for the last 7 episodes of season 2. They had to quickly re-cast the part of Iroh. The re-casting put a halt to production on season 3. Mako's part was succeeded by Greg Baldwin in the 3rd season.