Crazy Celebrity Halloween Costumes

Lady Gaga proudly showed off a more svelte figure in a barely-there weed costume. She captioned the post, "Happy Highlaween!!"

Jessica Simpson's daughter Maxwell Drew had a costume change, switching from a chicken to a monkey.

Hippie love! Jennifer Lopez linked arms with her super-toned boyfriend Casper Smart.

BFFs Katy Perry and Shannon Woodward paid homage to the MTV classic Daria.

Looks like Heidi Klum has some competition. Gisele made for a flawless Cleopatra.

Vanessa Hudgens and her sister Stella owned the night as sexy vampires.

The hosts of The Doctors retired their scrubs for the day, dressing as their favorite talk show host counterparts.

Clearly, Chloe Moretz's got spooky down.

Alyson Hannigan and family made adorable sparkly dragons.

Is this really a "Batman" costume?

Kate Moss and husband Jamie Hince went as Morticia and Gomez Addams.

Sexy Abraham Lincoln?! … at least it's creative.

Is she really 40 years old?!

Mariah made a gorgeous Goldilocks.

Neil Patrick Harris and David Burtka play Wizard of Oz with two-year-old twins Gideon and Harper in this adorable pic shared via Twitter.

Super-mommy Maria Shriver was snapped by daughter Katherine Schwarzenegger, cape and all, on Halloween day.

Clad in stripes and carrying a briefcase, Kal Pen looked ready for business decked out as Disney's beloved Tigger the tiger. 

Dwayne "The Rock" Johnson posted: "Don't make me angry.." "You wouldn't like me when I'm angry" ~ The People's Hulk. Happy Halloween!

Dressed as Goldilocks and the three bears, Maria Carey playfully poses with hubby Nick Cannon and 18-month-old twins Moroccan and Monroe.

Adam Shankman posted from the set of Glee: "Having a snack on, I mean, WITH @diannaagron"

Paris Hilton posted: "How do you like my Honey Boo Boo #Halloween costume?"

Kim Kardashian's mermaid get-up included a $2,000 blonde wig  ... wonder how much Kanye West's sailor suit costs?

A super-slim Jessica Simpson and family got into the Halloween spirit.

Fergie showed off her crazy figure as Angelyne next to an unrecognizable Josh Duhamel as Dennis Woodruff.

New couple alert? Patrick Schwarzenegger and AJ Michalka looked cozy at two separate Halloween parties.

Stacy Keibler made a pretty black swan.

Though her annual Halloween bash was canceled due to Hurricane Sandy, Heidi Klum took to Twitter to give us all a preview of her glamorous Cleopatra get-up this year.

The couple that dresses together stays together? Ryan Seacrest and girlfriend Julianne Hough made a pretty great Bonnie and Clyde duo.

Not exactly sure what costume Christina Aguilera is going for here (sexy-something for sure), but she certainly found her knight in boyfriend Matthew Rutler.

Lance Bass made for a surprisingly scary clown.

Neil Patrick Harris showed his dark side in this creepy, shirtless costume.

Adam Lambert and his boyfriend Sauli Koskinen went with dramatic 'Glampire' costumes.