Sud

"earth"

- My Earthbending master, Sud, was uncompromising, stubborn, and blunt ... and a life-long friend.

Sud was Avatar Roku's Earthbending teacher and taught him the bending art when the Avatar was in the process of mastering the four elements.

History
Not much is known about Sud except that he was a citizen of the Earth Kingdom when Roku was a young man and a skilled and powerful Earthbending master given the honor of teaching Earthbending to the Avatar, the last element Roku needed to master to become a fully-realized Avatar. The latter described him as being "uncompromising, stubborn, and blunt."

Once completed training, Roku beat his teacher in a race up a mountain by surfing on rocks. Sud seemingly pulled ahead at first, however, when he reached the top of the hill, Roku was already sitting there brewing a pot of tea and offered him a cup. Sud laughed, and they sat down to enjoy the hot beverage. Having mastered all four elements, Roku journeyed back to the Fire Nation in order to master the Avatar State there, but they remained very good friends afterward.

Trivia

 * Sud resembled the shadowed Earthbender in the Avatar opening sequence. His character design was confirmed by Mike and Bryan to be Toph's original design.
 * Sud is identical to the French and Italian word for "south." It is also close to the German "süden" and the Spanish "sur."
 * It is interesting to note that to be "south" is to be resistant to change or to be stubborn with new ideology, which are two main principles involved in Earthbending. In contrast, to be "north" is to be open to change, a principle involved with Waterbending. These two notions were paraphrased by Iroh when he explained the philosophy of the four nations to Zuko.
 * It also made him a counterpart to Toph, whose last name, Bei Fong, means "north."
 * Roku's description of Sud held many of the same traits that Toph held, and his earlier comment of friendships transcending lifetimes led to speculation that he was the past life of Toph or maybe Toph's ancestor.
 * Of the five benders featured in the Opening Sequence, Sud is the latest, and currently the last, to have been identified, after Roku, Pakku, and Azula. The shadowed Airbender has yet to be revealed.