Lady Blue is a blue fox who appears in the books and the TV series, although she is never named in the books. She is the mate of Scarface and like him, she is a normal red fox in the books, but she is changed into a blue fox in the TV series (which in reality is called a silver fox).
Her role in the books is very minor as she does not get involved in the feud between her mate and the Farthing Wood animals. In the TV series however, she is just as threatening to them as Scarface is, regarding Fox and Vixen as "common" and attacking Vixen in order to trigger an attack on them from her mate. She serves as a secondary antagonist in Series 2. Like the majority of the blue foxes, Lady Blue disappears after the second series.