Jimmy is a first cross between two fairly well known breeds. But it's obviously not that easy as no one has guessed correctly all month.
One parent is easy, the other more tricky. Hence I will issue a clue straight away.
One parent might be a bit busy at this time of year herding Rudolph and his mates....
Send your best guess to email@example.com
More clues on Twitter if no one gets it correct!
First correct answer wins a doggie book of your choice from the Interpet range - either breed books or general books.