Well, I can't think of any off hand. Of course, any snake has the potential of dying unexpectedly, for no observable reason. Just as can happen to human beings.
I check the animals for obvious problems like obvious kinks or any other visual defects. I'm not going to send you anything that I don't think as a fighting chance of surviving for you.
Quite frankly, if you are REAL new at this, this may not be the route you want to take. Most will eat for you, but those that won't will tax your patience.