|Physical appearance||Short, dumpy, face like a friendly raisin.|
|Residence||Tir Nani Ogg, The Square, Lancre Town, Lancre|
|Relatives||sister, Beryl Ogg|
|Children||Jason, Grame, Tracie, Shirl, Daff, Dreen, Nev, Trev, Kev, Wane, Sharleen, Darron, Karen, Reet and Shawn|
|Marital Status||Widow (Albert Ogg, Winston Ogg and Sobriety Ogg)|
|Books||Wyrd Sisters, Witches Abroad, Lords and Ladies, Maskerade, Carpe Jugulum, The Sea and Little Fishes, Wintersmith, I Shall Wear Midnight, The Shepherd's Crown|
|Cameos||Thief of Time, The Wee Free Men|
Gytha "Nanny" Ogg is a witch from the Ramtop Mountains, Granny Weatherwax's oldest and perhaps only friend, sometime conscience and reality-check. As skilled a witch as Granny, but in other ways, able to manipulate events and people (even Granny) by being herself – in capital letters – fond of a dram, or three; fond of a lad, or three; she is Granny's connection to a different world.
She lives in Lancre town and is the matriarch of a very big family. Two of her sons live in cottages on either side of her house, and when she needs either of them she only has to bang on the wall. It is said that housework to Nanny is something that happens to other people; Nanny stopped doing housework once her eldest daughter was old enough to hold a duster. Nowadays, Nanny's daughters-in-law come in to do her household chores; she bosses them rather nastily, and the trait is considered to be the only unpleasant thing about Nanny. While she knows every detail of the lives of all her grand- and great-grand-children and most of the rest of Lancre and their ancestors, she can never recall the name of a daughter-in-law.
Among Nanny's special talents are the ability to get along in any foreign language immediately by turning it into a pidgin that gets the message across, and a knack for producing a reasonable tune from any instrument she picks up. Her singing voice, when echoed by a half filled bathtub, causes birds to fall from the sky and goat milk to turn into yoghurt while still in the goat. Needless to say, the neighbors panic when they hear her drawing a bath. One of her favorite songs is The Hedgehog Can Never be Buggered at All, whose lyrics probably shouldn't be proclaimed so loudly in public places. More importantly, she has been selected by those who should know as the greatest midwife in history, and her command of practical magic is probably second only to Esmerelda Weatherwax's. Nanny Ogg's version of scumble (distilled, rather than frozen) is widely famous. It's made from apples, well, mostly apples; the mystery ingredients seem to give it power beyond mere alcohol. She must be deemed to be an irrepressible cook, and is the author of The Joye of Snacks and the inspiration for Nanny Ogg's Cookbook.
Nanny Ogg has a helmet of white hair like a very solid thatch. It is also said that there were dwarfs in the Ogg ancestry. In any case, the result is that it is difficult to knock Nanny out by hitting her on the head, an option not often contemplated but attempted at least once (see Maskerade) - even having a house drop on her head has not knocked her out (see Witches Abroad). She also has one single tooth left - Nanny eating a pickled onion with gusto is a sight not soon to be forgotten.
It has been mentioned (especially by Granny Weatherwax) that in her youth, Nanny had an enthusiastic appreciation for the company of men. In The Art of Discworld, it was also revealed that in her youth, she had dated Leonard da Quirm, resulting in his painting Mona Ogg.
Nanny says that the key is to remember where you left your clothes.
Unlike the names "Weatherwax", "Device" and "Garlick", the name Ogg came... from a phonebook.
The name Gytha was inspired by Gytha North, a British fantasy fan and acquaintance of Terry's, whose love of music, and involvement in the filk music scene was probably the inspiration for Nanny's penchant for singing.
There is an Ogg mentioned in the Harry Potter series.
Nanny's house's name, Tir Nanny Ogg.... in Irish Gaelic mythology, Tír na nÓg is the Island of the Blessèd (the literal translation of the Gaelic 'Tír na nÓg' is 'Land of the Young'), the Celtic heaven set in the far West, beneath the setting sun. No doubt Heaven for Nanny, but Purgatory for the daughters-in-law... It is also the Land of the Ever-Young perhaps fitting with Nanny Ogg's desire to never act her age.
The ancient Irish language Ogham appears in Discworld as Oggham. In Lords and Ladies, Nanny Ogg claims her ancestors invented the Oggham language, although she might have been having one over on Casanunda; however, she is able to translate the Oggham above the door to the Elf King's realm as "I've got a great big tonker."