Bosses can be found in the last space of every Region. They are unique in the fact that they are usually one rarity above any other cat or dog in the area, making them harder to defeat.
All Bosses, when first battled, are angry. This angered status makes them more powerful and prevents them from being caught. After a boss has been defeated once, the angered status goes away; it can then be captured in another battle. When Angry, a cat or dog will have skulls flying out of it, similar to an elusive cat.
Bosses are exactly the same in Woofshire; they are on the last battle spot, they are angry, and their angry status goes away once defeated.