Almost all BP's have alien heads...
This is a normal:
Black Pastels and Cinnamons have funked up alien heads
http://www.worldofballpythons.com/morphs/black-pastel/
http://www.worldofballpythons.com/morphs/cinnamon/
The biggest difference between a black pewter and a pewter is the base color. black pewters as the name suggests are more black
Pewter:
http://www.worldofballpythons.com/fi...pewter/013.jpg
Black Pewter:
http://www.worldofballpythons.com/fi...pewter/002.jpg