Harry Potter Alphabet Game

U - U-No-Poo

Vindictus Viridian

W - werewolf

X - X-ray look

Y - Yaxley (the Death Eater)

Z - Zonko's Joke Shop

A - Abraxan horse

EDIT: To make things easier, here's a list of things we've already used -

A - Albus - Arthur - Aberforth - Acromantula - Accio! Acid Pops! Aguamenti! Alohamora - Abraxan horse
B - Bezoar, Bertie Botts Beans, Bathilda Bagshot, Burrow - Bane - Baruffio - Beauxbatons - Bellatrix Black.
C - Cruciatus Curse - Chamber - Crouch - Centaur - Caterwauling Charm - Cornelius Fudge
D -Dark Mark, Death Eater, Disapparition, Daedulus Diggle, Durmstrang, Dementor
E - Erumpent - Elphick - Eeylops - egg - Eagle Owl - elf - Elder Wand - Errol
F - Fang, flying, Forbidden Forest, Ford, Feathers, Fanged geranium, firewhiskey, Firebolt, Fiendyfire
G - Gryffindor, Grubbly-Planck, Grawp, Gaunt, Goblins, Gellert Grindlewald, Gaunts, gargoyles, Gillyweed, Greyback
H - Harry, Hermione, Hogwarts, Hogsmeade, hippogriff, horcrux, Headless Hunt - Hagrid - hags - Halloween - Hinkypunk
I - Immobulus - Inigo Imago -Imperio - Incendio - Ice Mice
J - Jelly-legs Jinx, James, Jobberknoll, Jocunda Sykes
K - Karkaroff - Kreacher - Kneazle - Krum - Knockturn Alley - Kettleburn
L - Longbottom, Lestrange, Legilimency, Levicorpus - Luna - Lucius - Lumos - Leg-Locker - Liberacorpus
M - Minerva McGonagall - Mad-Eye - Magic - Muggles - Malfoy - Ministry - Madam Malkin, Mad-eye Moody, Madam Malkin
N - Nox, Nearly Headless Nick, Nargles, Niffler, Nimbus - Nagini - Norbert - N.E.W.T.s
O - October 31st, Oppugno, Occlumency, Ollivander, Obliviate, Order of Merlin, Owls
P - Padfoot - Prongs - Pansy Parkinson - Patronus - phoenix - Polyjuice Potion - Potter - Peeves - Peter Pettigrew - parchment - Parseltongue - Peppermint Toads
Q - Quidditch, Quirrell, Quaffle, Quest, Queerditch Marsh, Quick-Quotes-Quill
R - Riddle - Room of Requirement - Rat - Reparo - Reducto - Ravenclaw - Rosmerta - robes - Rune
S - Snape, Sectumsempra, Serpentsortia....snitch....Salazar Slytherin, Shell Cottage
T - thestral - time turner - treacle tart - Tonks - toerag - tea cozy - tea leaves - tasks - Tickling Charm
U - Umbridge (ugh!), Unbreakable Vow, Undetectable Extension Charm, unicorns.....U-No-Poo....Uric the Oddball
V - Voldemort - Veela - Veritaserum - Vampire - Viktor - Vane - venom - Vindictus Viridian
W - wizard, witch, Weasley, Wimgardium Leviosa, werewolf, Wimbourne Wasps, Wizangamot, Warlock
X - Xenophilius Lovegood, X-ray look
Y - Yaxley, Yeti, You-know-who, Yew wand, Yule Ball
Z - Zabini - zoo - Zonko's - Zephranthes? It's another name for ... Lily!

B - Burrow

C - Cauldron Cakes

D - Dragon Pox

E - Evans

F - Felix Felicis

G - Gobstones

H - Hedwig

Thanks for the list, Mona! It's just what we need!

I - Invisibility Cloak

J - jumper

K - Keeper of the Keys

L - lacewing flies

M - Mafalda Hopkirk

N - newt

O - Order of the Phoenix

P - passwords

Q - Quirrell

R - Rogue Bludger

S - Stupefy!