Fie was born some time after Thaegan's return to Deltora. Her father, if there was one, is unknown. She and her twelve siblings took over territory in Deltora's east, killing and eating anyone they could find.
The Deltora Book of Monsters
She and her siblings captured a group of travellers on the road 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, who gave him the details on Thaegan's children for his book.
Fie, Fly, and their nine surviving siblings — Hot, Tot, Zan, Zod, Pik, Snik, Lun, Lod, and Ichabod — all join forces to seek vengeance on Lief, Barda, and Jasmine, for the deaths of their mother and siblings. They pursue the companions as wolves and force them into a net trap. However, the siblings began fighting over how the food would be divided. Through Lief's encouragement the fighting became lethal, and Fie was felled by her brother Zan. She and all her siblings died, except for Ichabod.
Fie was a green monster with a large head and dripping brown fangs. She had markings on her strong arms, resembling tattoos. He has red eyes.[nb 1]
In the anime, he had a large swollen head and a blue tongue.
He also possessed strong magical powers, which, among others, gave him the ability to shapeshift, allowing him to turn into a massive wolf.
The children all survived their battle in the anime, and returned to help their mother get revenge on the companions. After her first ressuraction, Thaegan recruited Hot, Tot, Fie, and Fly, to disguise themselves as a girl named Françoise and lead the companions into a trap. However, thanks to the power of the Lapis Lazuli, one of Thaegan's spells missfired and killed all four of her children.
Like Jin and Jod before him, Fie returned as a Whill-o-the Wisp and remained with his living siblings when their mother returns for the second time. When their mother commits suicide, he followed after her with the rest of his siblings (minus Ichabod).