Katy Perry Gets Her ‘Boo!’ On

With her strict Christian upbringing, should Katy Perry be so big on celebrating Halloween?

Well, the spooky holiday coincides with Katy’s birthday (she turned 24 on October 25); so the singer threw a massive Halloween/birthday bash at Siren Studios in Los Angeles Tuesday night, reports E! Online.

Setting the tone for the event, so-gay Katy arrived at the festivities in a hearse, rocking a 10karat ruby and diamond necklace by jeweler Pascal Mouawad.

More than 200 costumed guests—including Josh Groban and Cisco Adler—packed into the Malibu Rum-sponsored event to creep each other out with their costumes.

Aside from guzzling rum concoctions, partygoers bobbed for body parts and made merry in a coffin photo booth and an execution chamber.

Guests were asked to dress as their favorite dead celebrity. Adorned with a bushy mustache, Katy resurrected deceased Queen frontman Freddie Mercury.

Good luck getting any girls to kiss you with that bristle-brush strapped under your nose.