“I’m going as your mom.”
“And I’m going as your dad.”
“And I’m going…to therapy.”
– The Fairly Odd Parents
Costumes spotted on campus:
Captain Jack Sparrow (in swaggering, drunken form)
Mario riding a papier-mâché Yoshi
Pumpkins
Ninja Turtle
An 18th century girl
Mummy
Cinderella
Steampunk galore
Batman
The King (of Burger King fame)
Hermione Granger
Hobbit (in bare feet, the freezing idiot)
Doctor
The Doctor (which is not the same thing as a normal doctor. Is it, fellow geeks?)
The medieval club in full regalia
And a whole host of babies dressed up as everything under the sun (the cutest is Janssen’s darling little cheeky monkey, even if they weren’t technically on campus)
I was thwarted, I had two really good costume ideas and wasn’t able to find crucial components to either of them. Next year, dumplings. True to expectation, Hennessy and I ran to the university bookstore on a break, and the red and green are already on display. Le sigh.
Small Dog Syndrome 
On first read, I thought you were referring to The Doctor of Star Trek Voyager fame. But alas, you mean a different nerdy hero.
I’m not sure if you can count the medieval club as a costume since they wear that most other days as well.