Founded by: Salazar Slytherin
Head: Professor Severus Snape the potions teacher who dislikes Gryffindor students, especially Harry, Ron, and Hermione. He always favors his students, and used to be a death eater. He wants the Defense Against the Dark Arts job very badly, but has been unsuccessful in achieving that position so far.
House Ghost: The Bloody Baron. He is the only one who can control Peeves.
House Animal: serpent
House Colors: green and silver
Characteristics: According to the sorting hat: Or perhaps in Slytherin,
They made their real friends,
These cunning folks use any means,
To achieve their ends.
Location: not exactly known, but it is towards the dungeon. The room itself is a dungeon-like room with greenish lamps and chairs.
Slytherin Quidditch team: Marcus Flint is the captain, Draco Malfoy is the seeker. They wear green robes and players chosen are more for size than finesse or skill, it seems
all fly on Nimbus 2001s.
The Slytherin team is the second best team and has won the Quidditch cup 6 ears in the row. Gryffindor did beat them the last time. They're good on the pitch not because of skill, but because of dirty tricks and unethical playing tactics.
Misc: Most of Voldermort's supporters (Death Eaters) were in Slytherin.