Zei

History
He is the head of the Anthropology Department at Ba Sing Se University. Professor Zei is a well-traveled, highly educated student of exotic cultures. His thirst for knowledge brings him to strange, remote, and often dangerous places. Zei is an eccentric man to whom knowledge is priceless. He gets very excited at the prospect of learning anything about history or the world around him. A map of his travels shows he's been everywhere in the world, except the Fire Nation. Even though he has discovered many lost civilizations over the years, he longed to find the "crown jewel" of ancient discoveries: Wan Shi Tong's library. Though he knew the library was somewhere in the uncrossable Si Wong Desert, he never managed to find it on his own. He does find the library with the help of Aang and his friends. When Wan Shi Tong discovers their plans against the Fire Nation they had drawn up using his information, he sinks his library under the pretension that his knowledge could never be misused ever again. As he and the others try to escape, Zei tries desperately to grab as many books as he can to take; eventually, though, he simply declares that he would rather stay "for eternity" than lose his life's work, and the others are forced to leave without him.

Voiced by: Raphael Sbarge

Trivia
There is only one zéi (賊) in Mandarin and it means 'thief,' which is in a way what an archaeologist is sometimes considered.