Check Out John Mayer, Skrillex & More At Katy Perry's Haunted Birthday Party In L.A.

by Alex Gilman · October 22, 2012

[Katy Perry with Neil Patrick Harris and David Burtka]

Statistically speaking, about 75% of us have already had our birthdays this year. How were your birthday parties? Oh, you had an ice cream cake? That's cool. I think Katy Perry might still have you beat, though. Sure, we already knew she was capable of tricked-out, celebrity-packed parties, but by taking advantage of her birthday's proximity to Halloween, we think she might have climbed into truly epic territory with a costume party guests like Neil Patrick Harris and Mia Moretti took very seriously. MORE>>