|Name||Mr Seth Petty|
|Physical appearance||Heavy, grubby|
|Marital Status||Married to Molly Petty|
|Books||I Shall Wear Midnight|
Seth Petty (usually addressed as Mister Petty) is the father of Amber Petty. He is described by Tiffany Aching's father as being good at those jobs requiring brawn and endurance but relatively little brain. Seth is, in fact, exactly the sort of man who would wholly justify Moist von Lipwig's description of the out-of-town drovers' pub in Ankh-Morpork, the Butcher's Eagle.
By occupation (and perhaps default) he is a drover, responsible for leading flocks and herds of the Chalk's sheep and cattle to Ankh-Morpork, where the usual processing in the Shambles leads to the butchers' shops being adequately stocked. His work as what can only be described as a pedestrian cowboy keeps him away for long periods of time, during which Amber's mother has tended to... host travellers passing through the village. This leaves Seth with a certain amount of doubt as to the exact parentage of Amber. If he knew either way, perhaps he would not be so filled with rage - Men with limited cognitive power can only get so introspective before the doubt expresses itself through the fist and boot.
Mr Aching says Seth used to be a nice boy - It was just that his father would "lay into (him) just for looking at him in a funny way". It seems he taught his son a lasting lesson: He would grow up into a large, strong man, and use this strength to regularly beat his wife.
When Amber becomes visibly pregnant by her tailor boyfriend - a man despised by Seth as being in a lady's profession - too much ale and introspection at the Scouring Fair finds its way out via his fists. In the family barn, he beats her so badly that she loses the baby, his future grandson. This is too much for the town to bear, the informal orchestra convenes to play the rough music for him. Tiffany Aching saves him from it; she administers a witch's judgement all of her own, then tells him to leave and never return. Even when cornered he tries to fight, but is finally convinced to leave (quickly) by a sample of his daughter's pain.
Despite the warnings, he comes back. Filled with remorse, Mr Petty returns to the barn where his grandson died, making a bouquet of nettles and lighting a candle (in a very flammable building) for the baby. He then attempts to hang himself from the rafters. The Nac Mac Feegle cut him down.
Mrs Petty takes him back, much to Tiffany's dismay, but Amber is taken to stay with the Feegles in the mound. The locals promise to keep a close eye on the Pettys. He is last seen at Roland and Letitia's wedding, looking clean but sheepish by his wife's side.
There is a reference in a history of Dutch religion to a Calvinist sect that offered bouquets of nettles in church - mainly in recognition of the fallen nature of mankind and that we are but weeds in god's garden, and as an act of sincere (and uncomfortable) penitence for sin. (but also because in a Puritan-minded faith, flowers were seen as ostentatious, gaudy, and out of place in the worship of God).