Gryffindor

Gryffindor values courage, chivalry and boldness. Its emblematic animal is the lion, and its colours are scarlet and gold. Minerva McGonagall is the most recent Head of House. Nearly Headless Nick is the house ghost. The founder of the house is Godric Gryffindor.

As this is the house to which Harry Potter belongs, its private quarters are the only ones that have been described in any detail (though Slytherin’s common room was described briefly in Harry Potter and the Chamber of Secrets), and its members tend to get the most attention. These are located in one of the castle’s towers, the entrance to which is located on the seventh floor and is guarded by a painting of the Fat Lady, who is garbed in a pink dress. She permits entry only after being given the correct (regularly changing) password. Behind her is a large common room, with a fireplace, and two staircases leading up to the boys’ and girls’ dormitories.

According to J. K. Rowling, Gryffindor corresponds roughly to the element of fire, which may partly be the reason for its colours.

It must be remembered that since Harry Potter is a Gryffindor, it receives the most favourable depiction.

[Spoilers Ahead]

Gryffindors are disliked by Houses such as Slytherin, according to Phineas Nigellus Black, because they apparently engage in pointless heroics. There might also be an element of jealousy; since the arrival of Harry Potter, Gryffindor has received a certain amount of publicity that they hadn’t had before. Harry and his fellow Gryffindors tend to win in a lot of circumstances which, when viewed from a Slytherin’s point of view, may be considered unfair. Examples of this include the last minute points awarded by the Headmaster, Professor Dumbledore, at the end of term feast, which conveniently put Gryffindor ten points ahead of Slytherin, or when Harry gets special permission from Professor McGonagall to have his own broomstick for the Gryffindor Quidditch team, even though first years are not permitted their own broomstick (Harry Potter and the Philosopher’s Stone). Another example is when Harry Potter is chosen as the fourth competitor in the Triwizard Tournament, and is accused of cheating, stealing Cedric Diggory’s thunder and craving attention.

[Description courtesy Wikipedia]