Kai is a mutt, he was originally supposed to be a Portuguese Water Dog, but the spotty short haired dog just didn't match. Here's the best picture found.

Kai is the brother of Kristopher and Kodi, the protaganist of the trilogy. Kai has a sound mind and is a smart dog, he is very resourceful and courageous. He is known to get out of sticky situations with ease. He is very skilled with two swords, which is quite a feat when you are not bipedular! He knows how to use virtually almost every weapon and finds that being a brother to two crazy dogs of different types is not wasy being the peacemaker.