Wolf spirit

The wolf spirit was a ferocious beast who attacked Team Avatar when they were traveling to Hira'a.

History
When Team Avatar was traveling to Hira'a in search of answers to finding Zuko and Azula's mother, Aang began feeling a strange urge to constrict his face, feeling the presence of the wolf spirit. He briefly saw the wolf spirit a short while after, before being distracted by Azula's quick desertion. The wolf spirit appeared again and attempted to gnaw off Sokka's head. When Aang tried to respectfully approach the spirit and reveal his position as the Avatar, the wolf spirit quickly attacked him instead. Team Avatar tried multiple ways of attacking the spirit, all to no avail, until Appa swiped the wolf spirit with his tail. It retaliated by throwing up a cloud of moth wasps which quickly surrounded Team Avatar. The spirit was eventually scared off by Azula's lightning attack that struck the moths.

Abilities
The wolf spirit had the ability to remain invisible to most humans, and could breathe moth wasps with that same skill. It was also able to consume fire, and could easily withstand physical attacks. The spirit possesses sufficient physical strength and endurance to hold his own in a fight with benders and large beasts, like a flying bison.

Trivia

 * The wolf has face-like markings on its chest that resemble the face Aang made when he sensed the presence of the wolf.
 * Before the wolf spirit encountered Team Avatar, it was seen drinking water from a stream near Ikem's campsite.