He could be any number of mixes, including Rottweiler, GSD, or Chow. Just because a dog may have some Chow in it, does not mean that their tongue will be blue. There is another breed that also has a blue tongue, but I can't for the life of me think of it right now.
One also can't predict personality by looking at those adorable pictures. Even if the Breed Mix was known, it still would not necessarily be a predictor of character, as who's to say which Breed impacted the personality the most.
He's an awfully cute little fellow.