Lief, Barda and Jasmine first encountered Gla-Thon when they were spying on Gellick using the Dreaming Spring water. Gla-Thon openly spoke about how she remembered when the Gnomes ruled Dread Mountain, and not the Ooze ToadGellick. Later, Gla-Thon and a battalion of gnomes pursued Lief, Barda, Jasmine, and Prin when they escaped from their trap. They cornered the companions, but before they could kill them, Lief and Barda convince the Gnomes to allow them a chance to kill Gellick in exchange for the gem on his forehead. While at first skeptical, Gla-Thon and the other Gnomes accept when Jasmine was saved from Gellick's poison through the power of the Ruby. She enters the treasury (where Gellick sleeps) with Ri-Nan and Fa-Glin to make sure the companions would not steal any gold. After Gellick's transformation into a tree, she welcomed the Kin back to Dread Mountain and bid the companions farewell on good terms.
Return to Del
Gla-Thon was chosen to represent the Dread Gnome tribe in the ceremony to find the heir to Deltora. She arrived in Withick Mire with one of the Kin, and later joined the resistance in rescuing Dain from Ichabod. She was captured and was to be publicly executed alongside the rest of the resistance, but escaped in the confusion caused by Lief.
The Sister of the South
Gla-Thon arrived in Del just as the Toran Plague broke out, preventing her from leaving the city. She injured Fidelis after he saved Lief from Paff's creature, thinking instead that the dragon was attacking her king (and later shows remorse for attacking him). When the Plague was revealed to be poison, Lief had her send word to Dread Mountain to bring its emeralds and amethysts to test and cure poisoned food and people. After Lief discovered the Sister of the South and summoned Fidelis, Gla-Thon arrived to warn him of the townspeople rallying to kill the dragon. She was attacked by Paff's creature, but Lief drew its attention from her by jumping into the pit containing the Sister of the South.
Like other Dread Gnomes, Gla-Thon has a short, sturdy body. Her hair is frizzy and brown. While serving Gellick, she, like the rest of the gnomes, had sickly pale skin from spending most of their time underground toiling for the Ooze Toad.
Gla-Thon has a deep respect for the Dread Gnome's ancestry, and wasn't afraid to openly speak about it in the presence of Gellick. She is well trusted by her people, as she was selected to represent the Dread Gnome Tribe in Withick Mire. She also has a natural love for treasure, and a strong sense of honour.
As a Dread Gnome, Gla-Thon is a capable archer, being able to hit Fidelis with her arrows from a distance.
Gla-Thon was one of the first Dread Gnomes willing to collaborate with Lief, Barda and Jasmine in Dread Mountain. After Lief became king, Gla-Thon was very loyal to him even though Lief thought he had deceived everyone including Gla-Thon when he told there was no Toran Plague. Gla-Thon even risked her life by shooting Fidelis with her bow when she thought he was attacking Lief.
Gla-Thon's role in the anime is largely the same as in the books, with some minor differences. In the anime, near the end of the series, she helped Lief regain the Emerald when the gems were scattered around the palace courtyard; she tied it to an arrow and shot it towards Lief with her bow, where he caught it in his hand.