Slytherin house values ambition, cunning, leadership, resourcefulness, and most of all, pure wizard blood. The house mascot of Slytherin is the serpent, and the house colours are green and silver.
The ghost of Slytherin house is The Bloody Baron. The Slytherin dormitories and common room are reached through a bare stone wall in the dungeons. The Slytherin common room is a long, low, dungeon-style room, located under the Hogwarts Lake, furnished with green lamps and carved armchairs. The room is described in the second book as having a greenish glow. It has a pure-blood bastion and a dark reputation.
The Sorting Hat claims that blood purity is a factor in selecting Slytherins, although this is not mentioned until the fifth book. There is no reason to believe, however, that Muggle-born students are not sorted there, merely that pure-blooded students are more desirable to that house, as there are several examples of half-bloods in the house.
