|“||I am the foremost master of forms and shapes in all of Oz. Go up against me, Liir, and you will see what form and shape of vengeance that I take against you.||”|
|— Mombey, speaking to Liir[src]|
In The Novels
Before the coming of the Wizard, La Mombey was an adviser to Pastorius, the Ozma Regent; some say she was distantly related to him. After the Wizard overthrew Pastorius, he gave the regent's baby daughter, Ozma Tippetarius, to La Mombey to keep and hide away forever. The witch transformed the princess into a kitchen boy she would call "Tip" and use as her personal servant.
For a good many years Mombey was a ferocious old hag, with bristles on her chin and a bent back that caused her to have to walk with a cane (Tip was often used as her ambulatory cane).
To get the appearance of a younger woman, she, with Tip in tow, traveled a week by sand sledge across the deserts surrounding Oz and came to the duchy principality of Ev, where she was met by the duchess (presumably Langwidere), who had the ability to change the shape of her head and body to whatever pleased her. It’s unknown what happed after that, but when they traveled back to Oz, they arrived in Gillikin and while the two of them were riding the train Mombey went to the powder room and returned as a younger, beautiful woman, much to Tip’s shock.
Mombey is mentioned by Mister Mikko and Professor Lenx as being the Eminent Pastor of the hamlet of Old Pastoria. She is long thought to be the one to pick up Munchkinland where Nessarose left it after she died. Mombey is said to keep to herself, though lacks the conviction of exceptionalism that Nessarose possessed.
She puts Dorothy Gale on trial for the death of Nessarose Thropp, as a distraction for her plan to attack the Emerald City. She also tries to forcefully recruit Animals into the Munchkinland army by casting a spell on the bridges in Bright Lettins, which prevents the Animals from leaving. Brrr, however, manages to push through it when rescuing Dorothy.
After having him captured and brought back to Colwen Grounds, Mombey transforms Liir into an elephant and threatens him with death if he does not help her decipher the Grimmerie. She also reveals to him that she was the sorceress who placed the human spell on Princess Nastoya. Mombey has Trism use Liir to help him perfect the spell to control her army of dragons, which are trained to fight Loyal Oz. After acknowledging each others choices, Liir agrees to follow Mombey's way.
With the Emerald City brought to its knees by the dragon attacks, a parley between Mombey and Emperor Shell is called forth in the city. During the subsequent conference for surrender, Mombey reveals that Liir is not dead in his elephant form. By using the Grimmerie to attempt to revert Liir to his natural form, Mombey uses a spell called "To Call the Lost Forward" however, something goes wrong, as the spell Mombey uses to summon back Liir, summons more than just Liir; the spell inadvertently also returns Tip to his true form (Ozma) and restores Rain's natural green skin.
She is imprisoned at the end of the novel after the return of Ozma.
Mombey takes on many appearances throughout Out of Oz, majority of the time appearing as a tall, striking woman with a compelling voice, however, she wears a glamour to disguise the fact that she is actually an old and decrepit witch.
In one scene she appears wearing a full shimmery-coppery silk garment draped, uncinched, from the fabric yoke at her shoulders. Her skin smooth, with a beautifully cut yet impassive face.
In another scene Mombey’s face appears less chiseled and more delicate, fragile, and sorrowful. Her hair in a crisp chignon, looking more dark and spikier. She is wearing another tidal barrage of silks, flowered with white petals against maroon.
Again later, Mombey appears more mature, with silvery blonde hair and painted lips. Here she wielded a magic staff.
Later Mombey appears with a head of flaxen-red hair and a stern and loving expression.
Around the end of the novel Mombey appears as a woman of gravity with a furrowed brow and slivering hair, and she walked with a cane.