Slytherin: Why the Snakes?
So, to finish up the House animal analysis, we have Slytherin. So analysis after the break!
This one is truly a house animal that fits fairly well, and it's hard to think of any viable alternates that define the house as much. For evil and ambition, we could say that wolves, or bats, or weasels or stoats would be something that could be it. However, none of these quite demonstrates the nature of slytherin as the snake. Snakes are venomous, some swallow prey whole, some strangle, but they are something that is debatably essential in it's nature, as the venom can be used as poison or as medicine, depending on how it's used.
They are symbols of temptation, and this goes back to so many stories, that the snake is a something that tempts individuals with knowledge, or in this case, greatness. Putting this into the role of Slytherin, we see the first way that it opens people up to that doubled edge. Knowledge itself can be used for great things, though it can always be used for great evil. Especially as some may pursue darker paths (What is a Horcrux Professor Slughorn) instead of using new-found knowledge to pursue cleaner goals to benefit all around them.
We also have the medical connotation from earlier, in the Rod of Asclepius, a greek symbol for medicine and healing, with the serpent intwined over the staff, meant to heal, and this gives notion to the house's rather excellent affinity with potions, as they reflect the nature of the serpent, a source of venom in poison, and for healing in the rod. There is also the Caduceus, the symbol of Hermes to demonstrate commercial ties (though this is what is often used in medicine as well, especially in the United States). This demonstrates Slytherin's aims for riches and glory.
As for Salazar himself, and the involvement of the basilisk, it becomes more complex. Slytherin, despite being a house of double edges in ambition, knowledge and progress being for better or for worse, the founder of the house seemed to demonstrate different aspects to this. Being a pure-blood fanatic, he did not wish to train muggles (though, if I would argue for it, I would say that this was out of a belief that the muggle-borns would be a security risk, but it appears it was more prejudice than rational thought). So with a that, what can be said of this "purity" aspect of Slytherin? Interestingly enough, the serpent is the only one of the Hogwarts animals with cold blood. It pushes its blood to a point where it is different from the usual. The snake is also an animal which, compared to the others would be inherently magical in its nature, fangs to be used in potions, skins to be used in potions, heightened senses and stresses that the snake is a far more magical creature than any of its peers
So what do you think of Slytherin being the snakes?