Just a note, as I have seen a few other people with the same trouble that I was having finding a P/P breed. I am using the pet tracker breeds addon to list breed when collecting pets through wild pet battles. I fought a rare P/B and caged him, when I pulled up my collection it was actually a P/P. So, make sure you aren't passing up the breed you are actually looking for due to mis-label.
Just a note, as I have seen a few other people with the same trouble that I was having finding a P/P breed. I am using the pet tracker breeds addon to list breed when collecting pets through wild pet battles. I fought a rare P/B and caged him, when I pulled up my collection it was actually a P/P. So, make sure you aren't passing up the breed you are actually looking for due to mis-label.