In January 2013, a python hitched a ride on plane, unfortunately exposed on the wing after getting sucked out of its hiding place.
Qantas 191 is a Cairns → Port Moresby flight on a DHC-8-400, probably the first of the day.
Having done walk-arounds for a Cherokee, I would like to think that I wouldn't allow such an event to happen on a small plane. On the other hand, I realize that it would be impossible to do a thorough inspection on, say, an Airbus A380.
What is a typical preflight inspection checklist for a Dash 8 or similar plane? Would it have included, for example, a visual inspection of the flaps that would have allowed the snake to have been spotted?