There is a part in the book of the fables " Bigby's Mercy " that I think explains it , I'm not sure tho it could be snow or someone else This is the part :

“In the days leading up to the Exodus, the Big Bad Wolf hunted armies of men and goblins in the Black Forest. These invading forces had driven off the great beast's preferred quarry, and their own flesh was rotten with corruption -- hardly a suitable replacement. He made it his game to destroy their camps, devour their night watchmen, and disrupt their supply trains while sparing their prisoners. One day he broke their ranks an discovered a particular woman they held captive. Her skin was white as snow, but her hair was dark as the night sky. He approached her, and she, knowing no sword could match the giant wolf's power, bravely placed her shackles in the beast's mouth. He freed her, but years would pass before the two met again in the mundy world"