Blaise Zabini was a Slytherin in Harry’s year (1991-1998) (PS7).
Blaise shares Draco’s prejudice against Muggle-born witches and wizards; he has a contemptuous and arrogant manner. Ginny considers Blaise a “poser.” (HBP7).
He is a member of the Slug Club due to his famous mother, who has had seven husbands. After the meeting with Professor Slughorn on the Hogwarts Express, Harry followed Blaise back to the Slytherin compartment to eavesdrop.
He is relatively skilled at Potions as he is in the NEWT class (HBP18).
Because of the ambiguity of his first name, many fans believed Zabini to be a girl until Half Blood Prince was published. He must have been born between September 1979 and April 21st 1980, as he was able to take the Apparition test on April 21st 1997 (for which you have to be 17) (HBP21, HBP22).