This guy has rub marks on either side of his chin, due to poking and prodding the top of his tub while trying to escape.  I've seen many times over the years and it never seems to get worse, especially if the snake is put into an enclosure where he doesn't feel like he needs to escape.  The marks may somewhat go away after a few sheds.  He's otherwise a great snake.  Very handleable and a great feeder on both live and f/t mice and rats.  I've priced him about 40% lower than his original price because of the defect.  If you are seriously interested in him, please let me know and I'll provide pics.