Cobra.

“Oh,you may not think I'm pretty,
But don't judge on what you see,
I'll eat myself if you can find
A smarter hat than me.
You can keep your bowlers black,
Your tops hats sleek and tall,
For I'm the Hogwarts Sorting Hat
And I can cap them all.
There's nothing hidden in your head
The Sorting Hat can't see,
So try me on and I will tell you
Where you ought to be.
Y ou might belong in Gryffindor,
Where dwell brave of heart,
Their daring, nerve, and chivalry
Set Gryffindors apart;
You might belong in Hufflepuff,
Where they are just and loyal,
Those patient Hufflepuffs are true
And unafraid of toil;
Or yet wise old Ravenclaw,
If you've a ready mind,
Where those of wit and learning,
Will always find their kind;
Or perhaps in Slytherin
You'll make your real friends,
Those cunning folk use any means
To achive their ends.
So put me on! Don't be afraid!
And you won't get in a flap!
You're safe in my hands(though I have none)
For I'm a Thinking Cap!!”
― J.K. Rowling, Harry Potter and the Sorcerer's Stone

“United States”
― David Baddiel, The Boy Who Could Do What He Liked

“Malfoy swaggered forward when his name was called and got his wish at once: the hat had barely touched his head when it screamed, ‘SLYTHERIN!’ Malfoy went to join his friends Crabbe and Goyle, looking pleased with himself. There weren’t many people left now. ‘Moon’ … ‘Nott’ … ‘Parkinson’ … then a pair of twin girls, ‘Patil’ and ‘Patil’ … then ‘Perks, Sally-Anne’ … and then, at last – ‘Potter, Harry!’ As Harry stepped forward, whispers suddenly broke out like little hissing fires all over the hall. ‘Potter, did she say?’ ‘The Harry Potter?’ The last thing Harry saw before the hat dropped over his eyes was the Hall full of people craning to get a good look at him. Next second he was looking at the black inside of the hat. He waited. ‘Hmm,’ said a small voice in his ear. ‘Difficult. Very difficult. Plenty of courage, I see. Not a bad mind, either. There’s talent, oh my goodness, yes – and a nice thirst to prove yourself, now that’s interesting … So where shall I put you?’ Harry gripped the edges of the stool and thought, ‘Not Slytherin, not Slytherin.’ ‘Not Slytherin, eh?’ said the small voice. ‘Are you sure? You could be great, you know, it’s all here in your head, and Slytherin will help you on the way to greatness, no doubt about that – no? Well, if you’re sure – better be GRYFFINDOR!”
― J.K. Rowling, Harry Potter and the Philosopher's Stone

“He pulled out the letter and read:   HOGWARTS SCHOOL OF WITCHCRAFT AND WIZARDRY   Headmaster: Albus Dumbledore (Order of Merlin, First Class, Grand Sorc., Chf. Warlock, Supreme Mugwump, International Confed. of Wizards)   Dear Mr Potter, We are pleased to inform you that you have a place at Hogwarts School of Witchcraft and Wizardry. Please find enclosed a list of all necessary books and equipment. Term begins on 1 September. We await your owl by no later than 31 July.   Yours sincerely,   Minerva McGonagall Deputy Headmistress”
― J.K. Rowling, Harry Potter and the Philosopher's Stone