A KK Parrot's slope on his forehead is an uninterrrupted slope. The BP has a notch right about at his eye level. And a KK tends to be a bit thicker...but not always.
well, i have both so i can answer this ! the biggest difference is the size and the mass, you'll know what i mean when you watch my video. this is a 75g tank, can you spot 3 of my kkp ! the rest are bp's !