The great thing about having celebrity friends: Being able to raid their wardrobes!

Kelly Osbourne showed off her Halloween costume for E!'s "Fashion Police" moments ago on Twitter, looking exactly like Katy Perry.

Sporting one of the singer's actual "Part of Me" tour costumes and a dark wig, Kelly flaunted her amazing weight loss in the glittery getup.

"I can't thank you enough for lending me your stage clothes," Osbourne tweeted at Katy after debuting the pic. "I hope I did you justice!!!"

We can safely say she did, right?!

Check out all the pics above to see the latest costume photos -- then sound off below and tell us who is your favorite!

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