Mab

Mab is a Faerie and the Queen of the Winter Court; she is the Queen of Air and Darkness. She is the twin sister of Titania,  and the mother of Maeve and Sarissa, who are twin sisters themselves. She first appears in Summer Knight.

Description
"You may serve, wizard, or you may be served. As a meal."

- Mab

As the Winter Queen, Mab is one of the most powerful fae. She and Titania are between about 1,000 and 2,000 years old—older than the Battle of Hastings, but younger than Nicodemus.

Throughout the series, she has shown unusual interest in Harry Dresden.

About 6' tall, with long white hair (usually described as flowing all the way down her back), she has green cat-slitted eyes, very pale skin, and lips the color of frozen mulberries. She is ruthless, and, although capable of compassion, she shows it very rarely. Mab is, however always good to her word. She was once mortal.

Her main goal in life is to maintain the balance between the two Courts and the protection of reality against the Outsiders. Since her court is tasked with defending against Outsiders that are constantly trying to invade, she will do absolutely anything to achieve this. She is also the creator of the Unseelie Accords.

Mab is also mildly concerned with the the spread of factually accurate information about Faeries among humans. A copy of Kinder- und Hausmärchen by the Brothers Grimm found in Arctis Tor is dedicated to her, possibly indicating that she was involved with its writing. Accordingly, her distaste for Disney's treatment of the supernatural is deep and obvious.

Mab's Voice
In Small Favor, she does not speak for herself but used Grimalkin as her "voice" instead. When she does speak, it is described as razor sharp and shakes the area where Dresden is, making his nose and ears bleed. Dresden reasons that the cause of this condition is because of her fury over the attack on Arctis Tor.

In Changes, Mab still has need of a translator, using the Leanansidhe to speak for her. She said it's for his sake so he doesn't scream in agony bleeding from his ears. The Leanansidhe stated that "her voice is part of her power" and her rage is too great to be contained.

In Cold Days, Mab states that the real reason she used Grimalkin as her "voice" was due to her anger that Maeve was possessed by Nemesis.

Summer Knight
"Yes. Wise enough to be afraid. To understand, at least in part. How does it feel, to know what you know, child?"

- Mab

In Summer Knight, under the name of Ms. Sommerset, she informs Harry Dresden that she has purchased his debt with his godmother, the Leanansidhe, telling him that she will make the contract void, if he will perform three tasks for her; the first being an investigation of the death of the former Summer Knight, Ronald Reuel. Thanks to Winter Knight, Lloyd Slate's betrayal, Mab offers Dresden the newly-opened position, in place of his two remaining favors, which he refuses.

Dead Beat
In Dead Beat, Dresden tries to call up his godmother for information about the Erlking, and gets Mab instead. Lea is apparently "tied up" and Mab is now in possession of her knife. Mab states that she hasn't yet found a replacement Knight, and that Lloyd Slate is still alive and being tortured. She makes him the offer again. Again, he refuses.

Proven Guilty
In Proven Guilty, both Lily and Maeve express concern that Mab is going insane. Mab's stronghold of Arctis Tor is invaded - presumably by the Black Council - and Dresden ends up accidentally dumping Summer fire (given to him by Lily), into Winter's wellspring, to some unknown negative effect. Mab has a small cameo, in which she winks at him, as he leaves.

Small Favor
In Small Favor, Mab shows up during the second attack on Harry Dresden by the Gruffs. Grimalkin substitutes for her voice and because of this, Dresden challenges her to prove that she is indeed, Mab. She does so by providing detail of their first meeting and then winking at him, as she did in Arctis Tor. She then shows Dresden how John Marcone was kidnapped and gives him his second task; rescue Marcone. She tells him that he has been chosen as her Emissary in this matter, though he can avoid involvement by taking up the Winter Knight's Mantle. Dresden again, refuses.

Dresden shortly realizes that Mab is playing a game of some kind. Musing on the reason she had a surrogate voice, he notes that Mab told him Summer's hit men were after him because she had chosen him as her Emissary. However, for that to be true, she had to have done so hours before they met, before Marcone had even been kidnapped. He discusses with Thomas Raith that she may be going insane, but that she still assisted him by hindering the gruffs with a blizzard.

Mab has taken away Dresden's knowledge of fire magic, and stolen his blasting rod in order to prevent him from attracting the attention of Summer.

After Jake the janitor leaves Dresden with a copy of The Two Towers, Mab again shows up, claiming that he has won the respect of The Watchman. When asked who that is, Mab states that of the four Archangels, she likes Uriel the most. She states that he is the most dangerous, and cautions Dresden against saying his Name. When she threatens to offer the Winter Knight's Mantle to Raith, Dresden claims that he does not belong to her and she forcibly corrects him, stating there is still one favor owed.

Dresden asks why she sent the Hobs to kill The Archive, and why she recruited him to stop the Denarians. Mab tells him that Nicodemus Archleone was in violation of her Unseelie Accords, and that one of the other Denarians, Thorned Namshiel, was owed punishment for being part of the attack at Arctis Tor.

Turn Coat
In Turn Coat, Harry Dresden remarks that although the White Council has Mab's permission to move through the woods, they are by no means safe. He is then shortly attacked by a number of giant spiders who do not believe him when he says that he is on speaking terms with Mab. They state that no mortal speaks to the Queen and lives.

Changes
"So many terrible things are done for love. For love will men mutilate themselves and murder rivals. For love will even a peaceful man go to war. For love, man will destroy himself, and that right willingly."

- Mab

In Changes, Harry Dresden worries what Mab would do if she had the knowledge that Margaret Angelica Dresden was his daughter. After he is left paralyzed, Dresden attempts to summon Mab and is instead transported to the Valley of the Stone Table, where the Leanansidhe acts as her translator. Apparently, Mab's true voice would cause Dresden to fall to his knees, screaming in agony and clawing at his bleeding ears. According to Lea, this is because Mab's voice is part of her power, and she is full of rage. Lea is not able to say what Mab is angry about. After giving his word that he will not suicide, Dresden offers to be her Winter Knight, under the conditions that she restores his body to full health; gives him enough time to bring his daughter to safety, the knowledge and strength to succeed; and that she won't ask him to harm those he loves. He is made Winter Knight by killing Lloyd Slate and then completing a "ceremony" with Mab herself.

Mab ensures the ceremony was broadcast to every creature in Faerie. After hearing about the ceremony, Sanya states that he saw Mab once, and that she was both beautiful and dangerous.

Ghost Story
"Death is a spectrum, not a line."

- Mab

In Ghost Story, the Leanansidhe admits that she was forced to sell her debt to Mab because of the taint from the athame at Bianca's Ball). Mab—with the help of Demonreach—fished Dresden's body out of Lake Michigan, and kept it alive for six months, while he was on a spiritual walkabout.

Cold Days
"I was mortal once, you know."

- Mab

In Cold Days, Mab puts Harry Dresden through seventy-seven days of tortuous "physical therapy" in which she tries to kill him in increasingly inventive ways in preparation of his tasks ahead. He also assigns Sarissa as a physical therapist. Mab holds a birthday party for him in which he has an altercation with Redcap. Mab orders Dresden to kill Maeve.

Later, Dresden deduces that Mab is unable to do so herself, due to her feelings as a mother and being filled with regret. In the end, she lost both her daughters in some manner. Mab tells Dresden that she was once mortal.

Mab does as needed to protect reality—protect the Outer Gates—which fall under the domain of Winter. Maeve is killed by Karrin Murphy, and her Mantle of Power is transferred to Molly Carpenter.

"Cold Case"
In Cold Case, she charges Molly Carpenter to collect the tribute the Miksani owe the Winter Court. While executing this order, deals with the Holy Ascension of Our Lord cult's kidnapping of some children of the tribe, trying afterwards to share sex with Carlos Ramirez. When he gets badly hurt by her Mantle of Power, Mab informs her that the children are the tribute the tribe owes the Court, and that Molly cannot escape her duty to collect them to be trained as soldiers against the Outsiders, and that her Mantle is bound to protect her virginity as embodiment of the Maiden aspect of the Triple goddess.

Skin Game
In Skin Game, she instructs Harry Dresden to cooperate with Nicodemus Archleone to fulfill a favor owed to him. In a confrontation on the matter, she informs him that once his task is completed, Dresden is completely free to deal with him. Later, Dresden realizes that Mab and John Marcone had planned the whole adventure to destroy both Nicodemus and his reputation to avenge his kidnapping of Marcone.

"Christmas Eve"
In "Christmas Eve", Mab pays a visit to Harry Dresden, who is intent to build a red bike for his daughter. Fulfilling one of her obligation to her vassals, she brings a present for her, a ring giving the bearer power over Winter.