Happy Halloween from Siegfried & Roy 🐯🐯

A photo posted by @nicolerichie on

Katy Perry may have stolen the show at Kate Hudson's Halloween party last night with her Hillary Clinton costume, but she wasn't the only famous face there!

We spotted Jessica Alba, Kendall Jenner, Nicole Richie, Emma Roberts, Gwyneth Paltrow and tons of other stars rolling up to the party, and some of them went all out with sexy and spooky outfits. Kendall had just attended sister Kylie's Halloween bash, so she was really cramming in the events last night!

Emma was nearly unrecognizable as a skeleton, while Gwyneth opted to hide under her cowgirl hat when we caught her with steady beau Brad Falchauk. We also caught Sacha Baron Cohen in a cow costume, and Nicole Richie's costume was pretty fab as well, though it doesn't appear as though the tiger in her trio is hubby Joel Madden. Or is it? We can't really tell from the face paint...

Click the gallery below for ALL the awesome pics!