It's called the "teddy bear dog." Half shih-tzu and half bichon frise. In Canada we refer to the Shih-Tzu and Bichon Frise cross as Mollydogs instead of teddy bear dogs. I have two of them and they are wonderful.
Buddy is a beautiful, unique Boston Terrier / King Charles Cavalier. He came from a breeder in the United Kingdom who had a little accident with a Boston Terrier, and what an amazing accident! looks like a mini boxer!