Which characters in 'The Monarch of the Glen' are monsters?

There are several characters in 'The Monarch of the Glen' that are not entirely human. There is Jennie, who is a hulda, a supernatural creature from Norway. There is the bald man and his mother, whose nature is not made completely clear, but who are strongly implied to be Grendel and his mother in some new form. Finally, there is Shadow himself, who is half-god and called a monster by Doctor Gaskell.