Wizards, Witches and Beings: Z
Zabini, Blaise 
(b. circa 1980)
Slytherin 1991-1998 (PS7).
Described as a "tall black boy with high cheekbones and long, slanting eyes." Blaise
shares Draco's prejudice against Muggle-born witches
and wizards; Ginny considers Blaise a
"poser."
(HBP7).
In the film of "Harry Potter and the Half-Blood Prince," the role of Blaise was played by Louis Cordice.
Zabini, Mrs.
A "famously beautiful witch" who "married seven times." Each of her wealthy husbands died a mysterious death, leaving her a lot of gold (HBP7). Blaise Zabini's mother.
Zamojski, Ladislaw 
Zeller, Rose 
(b. circa 1984)
Hufflepuff 1995 - 2002 (OP11).
Zograf
Bulgarian National Team Keeper at the World Cup in 1994 (GF8).
Zonko 
Founder(?) of Zonko's Joke Shop. Possibly a real person, possibly a made-up name or nickname. Zonko's went out of business in 1996 (HBP12).