Professor Severus Snape is the enigmatic Potions Master at Hogwarts School of Witchcraft and Wizardry, but it should be obvious to even the most dim-witted individual that he would much rather hold the position of being the Defence Against the Dark Arts professor, something he's extremely keen on.  The Head of Slytherin House, Snape tends to favour his own students, both in his classes and on the Quidditch field, where he also serves as an occasional referee.  Snape harbours a particular dislike for Harry and doesn't appear too friendly to Ron either.  Why will become clear as you read.

'Professor Quirrell, in his absurd turban, was talking to a teacher with greasy black hair, a hooked nose and sallow skin'.  This is J.K. Rowling's introduction to Snape in the first book.  Snape's hair is shoulder-length and always looks like it needs washing, and to complete the picture he has cold, black eyes.  When Snape first looks at him in the Great Hall, Harry feels a sharp pain in the scar in his forehead.  Why I will not tell you now, but it becomes clear in the later books.

'At the start of term banquet, Harry had got the idea that Professor Snape disliked him.  By the end of the first potions lesson, he knew he'd been wrong.  Snape didn't dislike Harry -- he hated him'.  Harry's first encounter with Professor Snape during the first Potions class at Hogwarts.  'Snape, like Flitwick, started the class by taking the register, and like Flitwick, he paused at Harry's name.
  "Ah,yes," he said softly, "Harry Potter.  Our new -- celebrity."'   It's obvious from the very start that Snape doesn't like Harry ... why is revealed later in the first book.

I happen to like Snape's character -- I think he's extremely interesting.  More and more is revealed about him through each of the books and I think Alan Rickman plays him wonderfully in the films.  That's him in the picture above (d'uh!).  From the moment he swept into the Potions classroom, I thought 'here is a character to keep an eye on'.  And I was right!  Snape is one of those you're never sure who's side he's on, but more than that I shall not reveal here.  If you want to know more, either e-mail me, or simply read the books for yourself!  Every one of them is really brilliant!
 

Extracts from Harry Potter and the Philosopher's Stone