The poor poppet is failure itself.
—Yackle regarding Elphaba, Wicked: The Life and Times of the Wicked Witch of the West
Yackle is a mysterious recurring character in Gregory Maguire's The Wicked Years.
In A Lion Among Men, Mother Yackle tells Brrr that she awoke from a stupor already aged. She had no memory of her prior life. She ventured out of the room she was in and into Shiz where she began her career as a clairvoyant. She saw a picture of the mythological Yackle Snarling and adopted the name, dropping the Snarling. It is later revealed she came from the Grimmerie and was created as a witness to the life of Elphaba Thropp.
Yackle has had many guises throughout The Wicked Years.
After she comes into existence, she works as a practitioner of pagan herbal magic and a prophet. She stays for a time in Shiz offering minor predictions, before leaving for the Emerald City. In this form, Yackle is described as a "saucy looking old-biddy from Shiz" who can hardly see her own hand.
After leaving Shiz, she works in the Lower Quarter of the Emerald City in a shop branded with an underground symbol representing the practice of alchemy. During Wicked: The Life and Times of the Wicked Witch of the West, Yackle provides Nanny with the pills that are supposed to prevent Melena Thropp from giving birth to a green child again (her first being Elphaba.) Instead, the strange magic remedy causes Nessarose Thropp, Melena's second child, to be born without arms and hardly able to support herself. Yackle drinks some of the Miracle Elixir Nanny brought (which Melena was given by the Wizard) and predicts that Melena's daughters will change the history of Oz.
In A Lion Among Men, Mother Yackle admits to Brrr that before Nanny's visit she was a fake and has no actual powers. After her first vision, induced by the Miracle Elixir, she began to have some powers of prophecy, which she used to keep track of Elphaba.
Some 15 years later, Yackle mistakenly predicts that Elphaba will be at the Philosophy Club, and becomes a doorman there to possibly protect her. However, she only sees Elphaba's college friends, since Elphaba and Glinda left Shiz that night for the Emerald City. This time she is described as "a crone, with random teeth and a shiny white-pink wig slipping westwards off her pearly scalp".
For well over twenty years, through Wicked, Son of a Witch, and A Lion Among Men, Yackle took up the job as a maunt at the Chapel of Saint Glinda in the Emerald City and at the Cloister of Saint Glinda in the Shale Shallows. She takes the name Mother Yackle and is described as a senseless old biddy by the other maunts.
Mother Yackle takes a heartbroken Elphaba under her wing at the Chapel of Saint Glinda after the murder of Fiyero Tigelaar. At some point, the two of them move from the mother chapel in the Emerald City to the Cloister of Saint Glinda in the Shale Shallows. When Elphaba, accompanied by Liir, leaves with Oatsie Manglehand to travel to Kiamo Ko, Yackle gives her the broom.
In Son of a Witch, Mother Yackle watches over Liir and Candle, locking them in a room together so they would have sex. She then helps the two of them escape from the Mauntery to Apple Press Farm, a disused orchard owned by the maunts. She remains at the Mauntery, and when Cherrystone comes to question the maunts about Liir, he blinds Yackle in an attempt to get information out of her.
About eight years later, Mother Yackle is ready to die but finds herself unable. She demands the other maunts lock her away in a crypt and leave her there. However, she survives, and a year later she reemerges upon the arrival of Brrr. He is there to question her about her interactions with Elphaba, the Wicked Witch, and she questions Brrr about his life. When the Company of the Clock of the Time Dragon arrives at the mauntery, it brings the Grimmerie with it. At the end of A Lion Among Men, Yackle is able to be reabsorbed by the book.
She makes a brief appearance in Out of Oz. After leaving Mockbeggar Hall, Rain and the others consult the Grimmerie and are faced with a illustration of Yackle, which indicates they should go South.