Blaise Zabini is a wizard and a student in Harry Potter's year at Hogwarts School of Witchcraft and Wizardry, where he was sorted into Slytherin House. He is a peripheral character, primarily known for his association with Draco Malfoy's circle, his arrogant and aloof personality, and his membership in Professor Slughorn's Slug Club. Though a Slytherin, Blaise is depicted as more independently-minded and less of a sycophant than cronies like Vincent Crabbe and Gregory Goyle.
Blaise Zabini began his education at Hogwarts in 1991 and was Sorted into Slytherin House shortly after Harry Potter. He is largely absent from the narrative for his first five years. His most significant appearance occurs in his sixth year, as detailed in Harry Potter and the Half-Blood Prince. On the Hogwarts Express, he was in a compartment with other Slytherins, including Draco Malfoy and Pansy Parkinson. He was personally invited by Professor Horace Slughorn to join the Slug Club in his private carriage. Slughorn's interest was sparked by Blaise's mother, a famously beautiful witch who had been married seven times, with each husband dying mysteriously and leaving her a large fortune. Blaise accepted the invitation but displayed a cynical and unimpressed attitude, particularly towards Draco Malfoy's boasts about his connections to Lord Voldemort. He also showed open disdain for Ginny Weasley when she was invited to join the group, referring to her as a “blood traitor.” He later attended Professor Slughorn's Christmas party. During the Battle of Hogwarts in Harry Potter and the Deathly Hallows, Blaise was presumably among the Slytherin students who were evacuated from the Great Hall by Argus Filch after Pansy Parkinson suggested they hand Harry Potter over to Lord Voldemort.
Blaise is described in the books as a tall, dark-skinned boy with high cheekbones and long, slanting eyes. Harry Potter notes that he has a “conceited look.” His personality is characterized by arrogance, vanity, and a detached cynicism. He is contemptuous of those he deems inferior, such as those with different blood statuses or family allegiances. Unlike Crabbe and Goyle, Blaise does not blindly follow Draco Malfoy. He is not easily impressed by Malfoy's claims and maintains a cool, independent demeanor, suggesting a more calculating and self-possessed nature than many of his housemates.
While no specific magical talents of Blaise's are detailed in the novels, his continued presence at Hogwarts through his sixth year indicates he was a competent wizard who passed his O.W.L. examinations. His selection for the Slug Club, while primarily based on his connections, implies he was not a poor student.