Gunth Mach was the One Daughter of the Acyl nest of K'Chain Che'Malle, meaning that she was bred to ultimately become a Matron. Her mother was Gunth'an Acyl. She was first encountered in the company of Redmask and Sag'Churok. Later she was among the K'Chain Che'Malle guarding Kalyth.
She was capable of transforming her body to accommodate a rider.
In Reaper's Gale
She and Sag'Churok accompanied Redmask as guardians. During the final battle against the Letherii, Sag'Churok and Gunth Mach turned on Redmask and killed him, presumably for putting the interests of the Awl above those of the K'Chain Che'Malle.
In Dust of Dreams
She was sent by her mother to search the world of humans for some way to allow her species to survive. She found Kalyth as Destriant, Stormy as Shield Anvil, and Gesler as Mortal Sword. The humans led the K'Chain Che'Malle in a victorious battle against the K'Chain Nah'ruk.
In The Crippled God
In the aftermath of the battle with the K'Chain Nah'ruk, Gunth'an Acyl had sacrificed herself, leaving Gunth Mach, now Gunt Wanderer, in charge of Acyl nest.
Deciding to help the humans fight their mutual enemy, the Forkrul Assail, Gunth Mach allowed her nest to accompany the Letherii, Grey Swords, and Bolkando armies to Kolanse.