This question caught my eye because I went on a date with a boy who had this surname back in high school. In addition to being a cute little animal, a badger was a grain salesman. It can also refer more generically to someone who peddles wares, rather than just specifically for grain. Think of this last name the way you would any other profession-based last name, like Bishop or Pope. The name refers to the profession that someone in the family held at one point in time.