Snurched from faith_king:

[jackwabbit]

Costumes to do, from A to Z:

A - Another Shipmate! (Galaxy Quest)
B - Bluntman (Kevin Smith Films)
C - Chronic (Kevin Smith Films)
D - Danger Mouse (Danger Mouse)
E - Enterprise Crewmember (Enterprise)
F - The Fro (The Fro)
G - Greatest American Hero (Greatest American Hero)
H - Hogwart's Student (Harry Potter)
I - Iceberg (G.I. Joe)
J - Jack Sparrow (PotC)
K - Kick Ass (Kick Ass)
L - Luna Lovegood (Harry Potter)
M - Mal (Firefly)
N - Ninja Turtle - Raph or Donny (TMNT)
O - Odo (Star Trek DS9)
P - Panthro (Thundercats)
Q - Q (Star Trek TNG)
R - Rebel Commando, Endor Gear (ROTJ)
S - Scarlett (G.I. Joe)
T - Tonks (Harry Potter)
U -
V - Voltron (Voltron)
W - Wolverine (X-Men)
X - X-Wing Pilot (Star Wars)
Y - Yoda (Star Wars)
Z - Zoe (Firefly)

So, I can't think of anything for U besides Uhura, and that's not happening for me. I mean, there's Ultraman, but I'm not a fan per se, so that's cheating. Hm...tough one! Ugnaughts from Empire. No. Um...hm.