Here's my proposal:
Appearance: Josiah is a large man, no stranger to ale and meat and with a physique that reflects the same. However, he's sturdy as an oak and possessed of the strength and size that are optimal for his trade. He is reasonably well-respected within the town, and is dedicated to his forge. He considers himself competent and takes pride in his work, but remains humble. In truth, his skills are only average but his whole-hearted commitment as well as his strength place him slightly above others of equivalent ability. He is earnest and fair in business, as in life. He earns his keep from the sweat of his brow, and raises his children with the intention that they inherit his modest lot as he did from his father and mother.
He has two children, named Jeremiah and Charity. Jeremiah is an intelligent boy of twelve. Josiah imagines that in time, Jeremiah will be teaching him but in the meantime he helps the boy to learn about the natural world. He seems to be at his happiest when he is either reading about plants and animals, or else hunting. He has strong legs as well as a keen mind, and Josiah hopes that in years to come he might tend horses as well as shoe them. However, his interest at times seems a little morbid. Where Josiah himself would have been frightened to discover a dead horse or see a hunting dog pass away, Jeremiah only inspects. In the same way, he picks over hunted animals to discover how and why an arrow caused death in the manner it did.
Charity is a well-mannered and devout girl. At fifteen years of age, her interests are exactly where they should be: embroidery, house-keeping and the finding of a husband. She has designs on the preacher's boy, Michael, and Josiah couldn't be happier with that. He has no knowledge of Latin or of higher matters: only that God is to be loved and feared, and that there is no place better for his daughter than closest to the Lord and his ministers. Yet she, too, finds the time to go wandering into the woods and has been known to come back with flowers and herbs that he doesn't recognise. A girl will pick flowers, true enough, but on one occasion Charity returned to her bed and the very next day the farmer's expecting cattle all gave stillbirths. It was a sorry sight and a wicked one to be sure, poor sicklied Bess, pressing teat to calves whose mouth wouldn't take suck for the cold of death. He'd hurried the children back inside to help with the iron that day. He dreaded to think what folk would have said if they'd heard little Jeremiah all a-talk about the cow's sickness of mind to nurse miscarriages, and their little spirits moaning and wailing in the square.
Josiah is a man of firm faith. He is a good man. And yet, he experiences 'visitations' each night from a black cat named Pete. After each visit he prepares for the nightmares that will follow. In his dreams, at intervals he dare not guess at but nearly always when the moon is full and frost covers the ground, he is told that It Is Time. Twisted faces rear up from the flames of his forge and remind him that the Devil is watching him. They tell him: salt the farmer's earth. Put out the eye of the witchfinder's dog. Strangle the lambs. Above all, remember that if he doesn't obey the Devil's servant, Black Peter, the watchful eye of Satan will fall upon his children. He has long suspected that he is already watching, ever since his dear Mildred passed, but he will do anything to preserve them. Even if it costs him his soul.