Bigby is the son of Winter and Mr. North (or the North Wind). Being the runt of the litter, he felt forced to prove himself to his six brothers and sisters, and wound up devouring the grandmother in the Little Red Riding Hood story. After this, he vowed only to pray on humans, but eventually traced down his estranged father, the North Wind, and wound up trying to kill him seven times. When the Adversary's armies came into his world, Bigby Wolf was outraged.
Bigby became sheriff upon coming to the New World. He was sheriff of Fabletown when Prince Charming becomes mayor but chooses to resign due to his dislike of Prince Charming, so Beast became the new sheriff. Cinderella was an agent of his.
Bigby Wolf encountered Snow White and Rose Red as captives, and freed them. When he went into exile, Snow White visited him and stabbed him with a knife that contained wereworlf blood, giving him the ability to take on human form, since he would have to pass as a human in order not to get killed by the Adversary's army. He eventually developed romantic feelings for Snow White and they eventually married and had seven "cubs", most of whom looked like crosses between wolf and human (their marriage occurred after he was elected sheriff).