What are some good Harry Potter costume ideas?

Q:What are some good Harry Potter costume ideas?

This Friday i am going to a harry potter midnight party. theres a costume contest and i am determined to win. i need some ideas for a good costume. (no harry, ron, or hermione.. something that screams "creative!" oh and no Fluffy.. my mom wont let me cut the heads off my stuffed animal dogs.. last year the "whomping willow" won first place.. also just a sidenote: remember i only have tomorrow and a little bit of friday to make this and i dont have a car to drive to the store.. so basically something creative that i can make from household items (no cutting off stuffed animal dogs' heads..)

A:

Be a house elf!
Easy, just rub a pillowcase in the dirt and throw it on, don't shower between now and Friday night, don't wear shoes and grow disgusting triangular ears.

Or, be Mundungus.
Try not to look human, wear a shabby coat w/stolen items hidden in it.

Tonks is another option.
It could be fun w/different colored hair and a 'Weird Sisters' tee.

Nearly Headless Nick could be fun.
Draw a bloody gash across your neck and walk around w/your head tilted to the side all night. Make sure to have an old Victorian-style ruff around your neck and wear funny poofy shorts from olden times.

Umbridge.
Just raid your mother's/grandmother's closet. Not difficult. :P
That's all I've got for ya. Have fun at the release party! (No costume contests at the one I'm going to :

you also can buy a harry potter costume for yourself, http://cosplaysky.com..you can try it.