Mario Kart

Whoever's doing the best with the ladies by midnight gets a shell to the head.

Gizmo

Don't get him wet.

From David

The Fantastic Mr. Fox

The perfect costume for George Clooney not to be harassed all night.

Rock Paper Scissors

One of them definitely heard one too many "wanna scissor?" lines.

The Peanuts Gang

With bonus banana girl!

From mjroyer

Lil' Jersey Shore

The ballpit at Chuck E. Cheese has seen some real drama.

From Cato

Hulk

He got angry enough just making the costume that he actually turned into the Hulk.

From joedjc

Optimus Prime

That clock behind him isn't melting, you're just too blown away by the awesomeness of the costume to see straight.

Batman Villians

Where's Batman? After all, he's his own worst villain, isn't he? Discuss.

Animal from The Muppets

I WANT TO EAT DRUMS!

Otto - Happy Gilmore's Caddy

He prepared for the role by bathing in a golf course lake beforehand.

Elliot and E.T.

E.T phone Spielberg for copyright infringement.

Darth Malgus and Eleena Daru

Just because Star Wars:The Old Republic isn't out yet doesn't mean Twi-leks aren't the sexiest species in the system.

Neytiri-Avatar

You better link with a Toruk if you want any chance with her.

Watchmen

I'm more into watching the watchwoman than the watchmen.

From B K

E.T.

"Damn, my phone's battery is dead. Can I borrow yours right quick, I need to phone home."

From Daniel

Batman and Catwoman

They totally get off on the forbidden love.

Mortal Kombat

Everyone else at the party, whether they chose to or not, was in the background pumping fists for each match.

Katy Perry and Russell Brand

I usually don't feel like dessert, but today I could make an exception.

Katy Perry and Russell Brand

This is what their baby will look like

2 children, 1 adult

The craiglist ads searching for a little person just didn't go as well as expected.

From Mike

Robocop

Built to defend justice in a dystopian society. Sadly, he was never programmed how to love.

Up

Hey…she's not Asian! Or fat! Or a little boy!

From nick

Grady Twins - the Shining

The question to ask isn't which one is the evil one. It's which one is the eviler one.

Officer Kane of the Nostromo

Had to kiss an actual Face Hugger, but it was worth it.

From GOALIE

Gumby and Friends

They're already made of clay, so it was surprising that they were so upset when someone threw a brick at them.

From TJ Hahn

Urkel and the Real Urkel (Jaleel White)

The guy going as Urkel-bot totally messed up by taking a bathroom break and missing the photo op.

From malachi Mott

Hellboy

What else was he supposed to go as with sideburns like that? And you better not say Wolverine because that's perfectly acceptable.

From bison175

Master Chief

Hopefully he doesn't respawn too far from his neighborhood.

Velociraptor

When life gives you a bunch of empty pizza boxes, make a Velociraptor.

From acostaworld

Big Daddy and Little Sister

This was a real challenge (for their marriage).

Buzz Lightyear: Space Ranger

Watch out or you'll get a laser pointer straight to the forehead.

Alan from The Hangover

Thank you, Zach Galifianakis. – Chubby Slobs

From IVIisfits138

Jack Skellington

This is Halloween, this is Halloween.

From Graeme Abraham

Star Wars Jamboree

"The R2D2 Costume is a trash can and a salad bowl."

Plastic Army Man

He rolled around all night on a skateboard.

From AlmostElmo

Marv from Home Alone

Just when you thought you were safe from the Wet Bandits.

Scarecrow from Arkham Asylum

The hardest part about this costume was climbing the tree in it.

The Justice Lego League of America

Who do you think won the 5K, Superman or Flash?

From jabronie25

The Simpsons Crew

… minus any of the actual Simpsons.

From ffokazak

Super Mario Kart

Plus there's a fully dressed koopa trooper operating the streetlight from inside.

From john

UP house

Pixar even makes better costumes than Dreamworks.

Boba Fett + Cargo

One unlucky friend had to breathe through a straw all night.

Kratos, God of War

Being the God of Peace just doesn't sound as awesome.

From Chris

Transformers (Optimus Prime and Bumble Bee)

Now let's watch Bumble Bee breakdance.

Ultimate Robot

5 years of dreaming, 2 months of work. 1 unbeatable costume (See below for video).

Betelgeuse

You know they're a serious fan when they spell Beetle Juice like that. You go girl!

Edward Scissorhands

The costume is really in the eyes.

From achapman

NYC Don't Walk/Walk

"We even blinked and turned off."

Working Apple iPhone 4 Costume!

"Just don't hold my costume here or here or I lose service."