Katy Perry goes undercover in her new music video

On 'Jimmy Kimmel Live,' Katy Perry revealed the theme and even a clip from her new music video for "Birthday." Turns out she went undercover to film it. Perry said, "I was sick of making gorgeous videos where I'm like, sexual..."

So, Perry dressed up as different fake birthday entertainers. Yes, this is her in costume, and she worked realbirthday parties. It was all filmed.

We have seen Perry play comedic characters before - like in her video for "Last Friday Night." But looks like in "Birthday," she takes on multiple personalities.

She told Kimmel this time she was inspired to go undercover by his prank video featuring a girl allegedly catching fire while Twerking. It went viral.

Perry prefaced the real vid with a much sweeter, literally, lyric video - one that focused on birthday cakes. According to the singer's Twitter, looks like we'll be able to see the whole video Thursday.