The Knowledge Seekers were the fox-like spirit assistants of the knowledge spirit Wan Shi Tong, operating in the Si Wong Desert. They traveled the world collecting old books and parchments to contribute to the vast archives of Wan Shi Tong's Library. The Knowledge Seekers were also designed to help library patrons, so anyone who had questions about a library book could expect assistance from these little spirits, who might then expect a treat in return.
When Aang, Katara, Sokka, Toph, Appa, and Professor Zei found a large tower in the middle of the Si Wong Desert, they were unaware that they were looking at the top of Wan Shi Tong's Library until, suddenly, a Knowledge Seeker appeared over a dune, carrying a scroll in its mouth. It approached the building then scaled the walls without effort, entering through a small window at the top of the tower, which made the group realize they were not looking at an ordinary tower; they had found what they had been searching for, the spirit library.
Later, inside the library, when Aang, Sokka and Katara discovered the remains of an old piece of paper that mentioned "The Darkest Day in Fire Nation History", one of the Knowledge Seekers led them to an ancient mechanical calendar that depicted the movements of the heavenly bodies and showed them how it worked. After entering the date from the parchment into the calendar, they discovered that a solar eclipse occurred on "the darkest day". Using this information, Sokka deduced that firebenders lose their bending during a solar eclipse. In return for its help, Sokka gave the "fox guy" a treat.
The knowledge seeker that appears to Team Avatar in the desert bears a similar resemblance to the real-world fox but without the mustache. It has four long legs, a triangle-shaped snout, and a tail. It has brown fur with a brighter patch of fur belown its mouth, at the end of its tail, on its forelegs and posterior body. Its eyes are black and narrow.
The Knowledge Seekers' close resemblance of foxes was likely due to the fact that, like owls, foxes are commonly seen as sly and intelligent creatures.
Knowledge Seekers may have been based on the Korean nine-tailed fox or kumiho, which is said to be a mystical creature that brought books to the king in a golden age.
The creatures may also hark back to the Japanese kitsune fox spirits that serve the goddess Inari. Like the knowledge seekers, kitsune also "sought knowledge" and were said to earn multiple tails as they gain more knowledge.
Despite the library being almost completely underground and that humans were banned from accessing its knowledge, the Knowledge Seekers still retrieved information, loyal to the library and to Wan Shi Tong.