A large difference between poisonous and non-poisonous snakes, so I’ve heard, is that non-poisonous snakes have round pupils as apposed to slitted (cat-like) pupils.
Not that this would help if one was wearing sunglasses.
JupiterOatmeal
Comics and Such By J. Lyons, Broadcasting from the 27 Inexplicable Moons of the Jovian Giant
