Ghost Wolf is one of the seven children of Bigby and Snow White. Unlike the rest of his siblings, he was born a zephyr, meaning that he is invisible and unknown to everyone except his family and a few others.
His birth unknown to everyone, except for Frau TotenKinder who sent a card to Snow at the Farm saying that having seven children doesn't mean that its a good thing, showing she knew of Ghost existence before his parents. Being born a Zephyr not only was he invisible but he needed to feed on air to survive, because of this he unintentionally caused a series of murders in Fabletown and the Farm claiming in total five fables lives by taking their air out of their lungs and causing them to suffocate, only doing so to feed himself as he said regular air tasted bad. Eventually, he managed to find his way back to his mother at the farm who realized his existence based on the card she had received from Frau and the fact that Zephyrs are created by a severe birth defect. Snow and Ghost shared an emotional but brief reunion as she was forced to urge him to flee out of fear of being discovered and then killed by his grandfather, the North Wind as he usually killed Zephyr because of there need to feed on air leading most to kill people indiscriminately.
She urged him to go and find his father Bigby.
He eventually managed to find his father before or during his stay in Alaska as he did know about Sarah and stayed with him during his exile while also begin given the name Ghost by his father. He aided his father during his mission into the Homelands. When his father reunited with Snow White, he shared a happy reunion with his mother.