Slytherin, founded by Salazar Slytherin, is one of the four houses of Hogwarts School of Witchcraft and Wizardry. When establishing the house, Salazar instructed the Sorting Hat to choose only students who possessed certain characteristics that he valued. These include cunning, resourcefulness, leadership, and ambition. Several members of Slytherin have a tendency to form groups, often acquiring leaders, which further exemplifies Slytherin's ambitious qualities.
The founder, according to the Sorting Hat itself, valued and favored pure-blood students. However, any student who possesses a different blood status can be placed in the house.
Its emblematic animal is a serpent and its colors are green and silver. There are two notable Heads of Slytherin; Horace Slughorn, who held the position twice (first retiring in 1981 and returning as headmaster in 1997 until shortly before 2016), and Severus Snape. The house's patron ghost is the Bloody Baron.
Slytherin corresponds roughly to the element of water, given that serpents are commonly associated with seas and lakes in Western European mythology, as well as being physically fluid and flexible animals. Similarly, in Celtic mythology, water is seen as a gateway to another world, leading to speculation that the element was chosen to symbolise the hope of many Slytherins for an entirely "pure" community. Its colours are also based on the waters surrounding lakes—which are often greenish in colour—and silver for the association with grey rainwater.
