In book 6, it is revealed this character bestowed upon themselves the moniker of "the Half-Blood Prince".
Snape
“Nitwit! Blubber! Oddment! Tweak!” are the words spoken by Dumbledore in the opening speech during this book.
Philosopher's Stone (Book 1)
Not sure JK needed to tell us this... but the book says there are 142 of them.
Staircases in Hogwarts
Dumbledore tells Harry he sees this in the Mirror of Erised
A Pair of Socks
What is the name of the potion which can change a person's appearance into that of someone else?
Polyjuice potion
In book 3, it is revealed that this wrongly-accused prisoner is, in fact, Harry Potter's godfather.
Sirius Black
What position does Harry play on the Quidditch team?
Seeker
This is the company name of Mr. Dursley's drill company.
Grunnings
This person was one of the founders of Hogwarts and the owner of the Sorting Hat... when it was just a hat.
Gryffindor
Harry Potter was gifted two broomsticks. The Firebolt was given by Sirius Black. But, his Nimbus 2000 came from this benefactor.
McGonagall
This is what S.P.E.W stands for.
Society for the Promotion of Elfish Welfare
This is an remedy given from Lupin to Harry in order to counteract the effects of Dementors
Chocolate
This is the age of Nicholas Flamel when he decided to destroy the philosopher's stone
665
Almost all Dark Wizards come from either Slytherin or Gryffindor. But, famously, this wizard came from Ravenclaw
Professor Quirrell
Harry first took the Knight Bus in "The Prisoner of Azkaban." How much does a ticket cost if it includes hot chocolate?
14 sickles
What was the name of the tree Harry and Ron crashed their car into?
Whomping Willow
Which type of insect is Ronald Weasley most afraid of?
Spiders
What chess piece does the Lovegood house resemble?
A rook
What is the name of the poltergeist that lives at Hogwarts School?
Peeves
In the movies, this magical school is made up of only women. In the books, it is multi-gendered.
Beauxbatons Academy of Magic.
In book 3, this is the type of dragon is drawn by Harry Potter during the Triwizard Tournament.
Hungarian Horntail
The Gaunts, Harry Potter, Voldemort, and Slytherin all have this unique talent.
Parselmouth
What is the name of the Weasley's house?
The Burrow
Who was flying with Mad Eye Moody when he died?
Mundungus Fletcher
In the Harry Potter Books, April Fools Day is famous for what reason.
The Weasley Twins' Birthday