Zan was born sometime after Thaegan returned to Deltora. His father, if there was one, is unknown. Zan and his twelve siblings roamed Deltora's northeast, terrorising the countryside.
The Deltora Book of Monsters
Zan and his siblings captured a group of travellers and ate all but one before falling asleep. The man was able to escape, though he had no memory of anything before the incident. Josef met this man, and learned from him information about Thaegan's children for his book.
Zan and his ten surviving siblings — Hot, Tot, Fie, Fly, Zod, Pik, Snik, Lun, Lod, and Ichabod — join forces to take vengeance on Lief, Barda, and Jasmine for the deaths of their mother and siblings. As wolves, they pursued the companions and caught them in a net trap. Lief tricked them into fighting one another over how to evenly divide the three travellers between the eleven siblings. Zan felled his sister Fie, and was in return attacked by his brother Fly. The fighting became lethal, and Zan and all his siblings died, except for Ichabod. 
Zan was the second largest of Thaegan's children. He had six legs, his skin was light brown and he had a mouthful of large fangs with the red gum showing. His two hands, as well as every feet, had long claws, and two long shapes protrude out from the sides of his head, like horns.
Zan possessed strong magical powers, which, among others, gave him the ability to shapeshift, allowing him to turn into a massive wolf. He was also incredibly strong in combat.
Zan's role is expanded upon in the anime—along with all his siblings. He survived the battle that killed his book counterpart, and teamed up with Zod, Pik, Snik, Lun, Lod, and Ichabod, when Theagen returned for the second time. He was sent inside the Mirror of Fear and helped Zod torment Jasmine with a block puzzle until Lief ejected them all. When Thaegan committed suicide, Zan followed after her with his siblings (except Ichabod).
In the anime, he was coloured purple with a shark-like head. He lacked arms as well, instead using his first pair of legs to grasp objects.