Falon was the largest mortiwraith to ever live, and resembled a giant snake with many legs and bat-wing like ears.
Exerpt: Aidan stared and realized with dreadful certainly that it was a leg sticking out of the wall-a leg ending with a four-toed foot and razor-sharp talons... a monstrous, snakelike body with innumerable pairs of clawed legs. From the middle of the spiraling body arose an enormous round head, with creased ears folding backward and mingling with tufts of dark purple fur. Its eyes were moon yellow split by black, fanglike pupils.
Falon is first seen disguiseing herself as a maze and allowing Aidan to enter. When Aidan found the hidden treasure, she revealed herself (see exerpt above) and prepared to kill him. However, she noticed Fury and asked where he got it. Upon telling her that it was given to him by Captain Valithor, she remembered when Valithor rescued one of her offspring (possibly Faethon or Timera) from some Paragor knights. She spared Aidan and befriended him, helping him to rescue his friends.
In the third book, Falon saves Aidan and Antoinette from being frozen in the stilling, and became able to move about freely when the wyrm lord's black breath shrouds the realm. She participates in the battle of Alleble, decimating the enemy's infantry. It is here that she meets Robby and accompanies the trio when they confront Paragor. She is knocked out by the Wyrm Lord, and remains absent for a time. She eventually returns and sacrifices herself to save Aidan from the Wyrm Lord.
Falon was evil, sly, and merciless before meeting Aidan, and always hated Paragor for slaying her kind to use their venom in arrows. However, she soon proves to be quite caring and loyal; rescuing Aidan's friends, saving him at the cost of her own life, and caring for her young. But she does let bits of her sinister nature slip out sometimes, talking maliciously about killing the enemy and taking revenge for their deeds.