By Antoinette Bueno
6:08 PM PDT, November 1, 2012
Lady Gaga proudly showed off a more svelte figure in a barely-there weed costume. She captioned the post, "Happy Highlaween!!"
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Weed Whacker

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

Jessica Simpson's daughter Maxwell Drew had a costume change, switching from a chicken to a monkey.
Jennifer Lopez & Casper Smart

jenniferlopez.com
Hippie love! Jennifer Lopez linked arms with her super-toned boyfriend Casper Smart.
Katy Perry & Shannon Woodward

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

Vanessa Hudgens and her sister Stella owned the night as sexy vampires.
A Day Off
The hosts of The Doctors retired their scrubs for the day, dressing as their favorite talk show host counterparts.
Alyson Hannigan

Splash News
Alyson Hannigan and family made adorable sparkly dragons.
Ashley Tisdale

Splash News
Is this really a "Batman" costume?
Kate Moss

Splash News
Kate Moss and husband Jamie Hince went as Morticia and Gomez Addams.
Victoria Justice

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

Splash News
Is she really 40 years old?!
Mariah Carey & Nick Cannon

Mariah made a gorgeous Goldilocks.
NPH and David Burtka With Twins Gideon and Harper

Twitter
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.
Maria Shriver

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

Twitter
Clad in stripes and carrying a briefcase, Kal Pen looked ready for business decked out as Disney's beloved Tigger the tiger.
Can You Smell What The Hulk is Cooking?

Facebook
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!
Nick Cannon, Mariah Carey & Dem Babies

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

Instagram
Adam Shankman posted from the set of Glee: "Having a snack on, I mean, WITH @diannaagron"
You Better 'Pink'-neckognize

Paris Hilton posted: "How do you like my Honey Boo Boo #Halloween costume?"
Kim Kardashian & Kanye West

Splash News
Kim Kardashian's mermaid get-up included a $2,000 blonde wig ... wonder how much Kanye West's sailor suit costs?
Jessica Simpson & Eric Johnson

lifestyle.jessicasimpson.com
A super-slim Jessica Simpson and family got into the Halloween spirit.
Fergie & Josh Duhamel

Instagram
Fergie showed off her crazy figure as Angelyne next to an unrecognizable Josh Duhamel as Dennis Woodruff.
Patrick Schwarzenegger & AJ Michalka

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

Getty Images
Stacy Keibler made a pretty black swan.
Heidi Klum

Twitter
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.
Julianne Hough & Ryan Seacrest

Instagram
The couple that dresses together stays together? Ryan Seacrest and girlfriend Julianne Hough made a pretty great Bonnie and Clyde duo.
Christina Aguilera & Matthew Rutler

Splash News
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

Splash News
Lance Bass made for a surprisingly scary clown.
Neil Patrick Harris

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

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